Open access peer-reviewed chapter

Recent Developments on the Properties of Chalcogenide Thin Films

Written By

Ho Soonmin, Immanuel Paulraj, Mohanraj Kumar, Rakesh K. Sonker and Pronoy Nandi

Submitted: 17 December 2021 Reviewed: 03 January 2022 Published: 07 March 2022

DOI: 10.5772/intechopen.102429

From the Edited Volume

Chalcogenides - Preparation and Applications

Edited by Dhanasekaran Vikraman

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Chalcogenide thin films have attracted a great deal of attention for decades because of their unique properties. The recent developments on thin film-based supercapacitor applications were reported. As a result of sustained efforts, the experimental findings revealed remarkable properties with enhanced fabrication methods. The properties of perovskite solar cells were discussed in terms of crystal structure and phase transition, electronic structure, optical properties, and electrical properties. Perovskite solar cell has gained attention due to its high absorption coefficient with a sharp absorption edge, high photoluminescence quantum yield, long charge carrier diffusion lengths, large mobility, high defect tolerance, and low surface recombination velocity. The thin film-based gas sensors are used for equally the identification and quantification of gases, and hence should be both selective and sensitive to a required target gas in a mixture of gases. Metal chalcogenide materials are considered excellent absorber materials in photovoltaic cell applications. These materials exhibited excellent absorption coefficient and suitable band gap value to absorb the maximum number of photons from sun radiation. The photovoltaic parameters were strongly dependent on various experimental conditions.


  • thin films
  • semiconductor
  • band gap
  • solar cells
  • sensor
  • chalcogenide materials
  • supercapacitor
  • power conversion efficiency

1. Introduction

Chalcogenide thin films have attracted a great deal of attention for decades because of several reasons such as earth abundancy, environmental friendly [1, 2, 3], excellent structural [4, 5, 6], electrical [7, 8, 9], and optical properties [10, 11, 12]. These materials could be employed in various applications such as solar cells [13, 14, 15], ultraviolet light emitters, laser devices [16], spin functional devices, gas sensors, transparent electronics, corrosion resistant coating [17], microelectronics [18], optics, magnetic and acoustic wave devices. Several deposition methods including chemical vapor deposition [19], physical vapor deposition [20], sputtering [21], SILAR, spray pyrolysis [22], chemical bath deposition [23, 24, 25, 26], vacuum evaporation method [27], and electro deposition method [28, 29] have been used to produce thin films. Generally, these deposition methods could be divided into physical method and chemical techniques. Researchers highlighted that the chemical deposition method has many advantages such as inexpensive, and convenient for large area deposition [30, 31, 32].

Supercapacitor has been considered as one of the potential energy storage systems. The redox electrochemical capacitors and the electrochemical double layer capacitor have been extensively investigated by many researchers. Researcher reported that transition metal oxide, conducting polymers, and metal oxide thin films have been tested in supercapacitors. The perovskite structure consisted of the crystal structure of calcium titanium oxide. This material showed high absorption coefficient with a sharp absorption edge. The organic-inorganic hybrid perovskites based solar cell was made from sandwiching a perovskite absorber layer between the electron transport layer and hole transport layer. The obtained solar cells showed some unique advantages such as low-temperature processes for all sub cells, compatibility with flexible and lightweight applications. The thin film-based sensor could be used to convert physical or chemical quantity into equivalent electrical for measurement. Sensor is critical in improving the reliability and efficiency of manufacturing operations by providing faster and more accurate feedback regarding product quality.

In this book chapter, thin film based solar cell, thin film based supercapacitor and thin film based sensor will be discussed. The properties of the obtained films were reported. Lastly, the advantages and limitations of these materials will be highlighted.


2. Thin film based supercapacitors

Recently electronic devices such as computers, roll-up displays smartwatches, mobile phones and other portable devices abound in the twenty-first century. For greater performance, improved energy storage devices are required to reduce the energy consumption of these smart electronic devices [33]. As a result, devices with long-lasting battery, high power outputs, and quick recharge times are required. As a consequence, it is critical to create innovative energy storage materials and devices. The realities of scarcity of fossil fuels, and environmental damage should all be considered in this endeavor [34]. By modify the surface properties of the electrodes with a long life cycle, the supercapacitor (SC) is such an effective energy-saving technology that is environmentally friendly with quick charging, and high energy density are just a few of the benefits [35]. However, this redeemer (supercapacitor) has issues. Nevertheless, in comparison to lithium batteries, such savior (supercapacitor) has challenges such as poorer energy density, unavailability, and the high cost of ruthenium (IV) oxide (RuO2) and platinum electrode materials, all of whom have stymied the supercapacitor development. Supercapacitors, which are versatile, compact, ecologically benign, and yet still economical energy storage devices, are in growing market. The flexible supercapacitors, which bridges the gap between batteries and traditional capacitors, is a bright spot in the realm of energy-saving engineering. Flexible-all-solid-state thin film supercapacitor, an innovative novel thing, has gotten a lot of interest as unique energy storage devices because of its friendly construction, compact size, easy handling, and excellent power density with a quick charging-discharging rate. The supercapacitor is called as electrochemical capacitors it has a fast charging and discharging properties, excellent power density and high specific capacitance with compact construction, and inexpensive cost of maintenance. The three primary mechanisms of supercapacitor can be classified (Figure 1), which is depending of the reversible redox reactions and the accumulation of charge. There is electric double layer capacitors (EDLC), pseudo capacitor, and the combination of EDLC and pseudo capacitor called the hybrid supercapacitor [36].

Figure 1.

Classification of supercapacitors.

Thin films are very intriguing in modern research for a variety of applications in ethanol sensor, photocatalytic, thermoelectric and supercapacitor [37, 38, 39, 40]. The supercapacitors can store the electrical energy for all the electronic devices to stabilize the power supply. Generally, to prepare a pseudo capacitive electrode transition metal oxide (TMO) is the most popular approach, however relatively higher electrical resistivity restricts whose use several fields. As a consequence, the focus of researchers is turning to metal chalcogenides, which have a lower electrical resistivity than oxygen due to sulfur’s low electronegativity. The preponderance of these metal chalcogenides, mostly sulfides, are made from inexpensive and abundant transition metals. For example, Dai and co-workers [41] have prepared hierarchically structured Ni3S2 and multi-walled carbon nanotube (MWCNT) composites using the hydrothermal methods and the prepared device can have obtained the maximum Cs of 55.8 F g−1, it provides a highest energy density of 19.8 Wh/kg at power density of 789 W/kg. Xiao and co-workers [42] prepared a nickel cobalt sulfide nanoparticle graphene-based sheet (NiCo2S4@GR) there is no surfactant through simple one-step solvo thermal method, which results revealed the maximum Cs of 1708 F g−1 at a current density of 1.0 A g−1, while comparing without graphene. Mukkabla and co-workers [43] reported a Poly(3,4-ethylenedioxypyrrole) (PEDOP) Enwrapped bismuth sulfide (Bi2S3) nano flowers hybrid flexible SCS, and composite offered a maximum Cs of 329 F g−1 at 0.4 A g−1. Furthermore, these are usually undergoing redox reactions between the metallic ions valence states. Besides, TMO and transition metal chalcogenides, various metal nitrides have previously been observed has outstanding results as electrodes in supercapacitors and lithium ion batteries with impressive results. Recently, metal nitrates also have superior abilities in electrochemical properties with excellent chemical stability. Metal nitrides have gotten a lot of interest as supercapacitors electrodes since they have a lot of benefits. Metal nitrates have three major advantages. (1) It has a high σ (electrical conductivity) of 55,500 S/cm−1 while compared to the metal oxides as a result shows the excellent power density, (2) compared to the metal oxides and carbon based materials metal nitrates have a higher specific capacitance, which results shows the higher energy density, and (3) high mechanical stability. These characteristics make them extremely promising as high-performance supercapacitor electrodes. Balogun and co-workers [44] have summarized the performance of different metal nitrides like molybdenum nitrides (MoN), nickel nitride, titanium nitride. Among these metal nitrides, molybdenum nitride was considered as the first metal nitride which could be used as supercapacitor electrode materials. However, for supercapacitor applications, researchers mostly considering their materials cost and electrochemical performance. There are many transition metals and metal oxides are considerable for supercapacitor applications such as CuO, NiO, Mn3O4, Co3O4, Ni or CuCo2O4 and Ni or CuFe2O4 [45, 46, 47, 48, 49, 50]. Compared to the other metal oxides, the metal ferrite based materials much attracted to the researchers. For example, Fe, Ni or Cu based Fe2O4 materials have an excellent performance in the energy storage applications. There are two major methods could be used to prepare the thin films supercapacitors, namely physical technique (physical vapor deposition and sputtering) and chemical method. The successive ionic layer adsorption and reaction (SILAR), spin coater, and chemical bath deposition (CBD) are some examples for chemical deposition method (Figure 2).

Figure 2.

Thin films deposition techniques.

Bandgar and co-workers [51] studied the nature of starting materials on the properties of NiFe2O4 thin films for flexible supercapacitors. There are several morphologies could be observed (nanosheet, flower, and feather) through different salts such as nickel(II) chloride hexahydrate (NiCl2·6H2O), nickel nitrate [Ni(NO3)2·6H2O], and nickel sulfate hexahydrate (NiSO4·6H2O), respectively. The nanosheet based electrode material received the maximum Cs of 1139 Fg−1, nanoflower and feather achieved the good Cs of 677 and 435 F g−1, respectively. Immanuel and co-workers [52] have optimized the Cr doped Mn3O4 thin films for high performance supercapacitors using the SILAR method. The experimental results showed that 3 wt % of Cr doped Mn3O4 thin films exhibited the maximum Cs of 181 Fg−1 at the current density of 1 Ag−1.

Jesuraj and co-workers [53] studied the pristine and Li doped NiO thin films using the spin coating method. Kin and co-workers [54] prepared the carbon based flexible supercapacitors using the chemical vapor deposition. Yu and co-workers [55] have prepared the cobalt nickel oxide and sulfide heterostructure thin films through electrodeposition method for supercapacitor applications. The obtained findings revealed the maximum energy density of 78.2 Wh·kg−1 at 542.8 W·kg−1 and the high power density of 5440.2 W·kg−1. Recently, Immanuel and co-workers [56] synthesized Mn3O4 nanorod thin films via SILAR method. The prepared Mn3O4 thin films showed the maximum Cs value of 295 Fg−1 at the scan rate of 2 mVs−1. Vivek and co-workers [57] prepared a reliable electrode material, and results obtained a maximum Cs of 426.40 Fg−1 at a current density of 1 Ag−1. Arulraj and co-workers [58] prepared the cubic shaped Ag2S using the CBD method on Ni mesh. The prepared Ag2S used a working electrode, which electrochemical performance showed the highest Cs of 179 C/g at constant charge and discharge current density of 1 A/g.


3. Thin film based perovskite solar cells

Any materials which have the crystal structure of calcium titanium oxide (CaTiO3), were known as the perovskite structure and the materials have stoichiometry of ABX3; where “A” is the larger cation, “B” is the smaller cation and “X” is the anion. Each unit cell of ABX3 crystal comprises of corner sharing BX6 octahedra, with the “A” moiety cubo-octahedral cavity. In case of organic-inorganic hybrid perovskites (OIHP), halide anions (I, Br, Cl) are found at the “X”-site anion instead of oxygen, while monovalent (CH3NH3+, CH(NH2)2+) and bivalent (Pb2+, Sn2+) cations occupy the “A” and “B” sites, respectively. Halide perovskites were first reported by Moller in 1958 for cesium lead halides [59]. Further, it was also observed that small organic molecules with effective radii less than 260 pm [methylammonium (MA), formamidinium (FA), hydrazinium, hydroxylammonium) can also accommodate inside the PbX6 octahedrons. The word “hybrid” indicates that the crystal is made specifically by the combination of “organic” and “inorganic” components. The architecture of OIHP-based solar cell is quite simple and prepared by sandwiching a perovskite absorber layer between the electron transport layer (ETL) and hole transport layer (HTL). A standard OIHP based solar cell device has a structure composed of glass/ transparent conductive oxide (TCO)/TiO2 (ETL)/ mesoporous TiO2 (mp-TiO2)/ perovskite (~500 nm)/ HTL/ metal and a quite high efficiency exceeding 20% can be realized without including complicated processing steps. The operation of the perovskite device is sstraight forward; namely, the photo-electrons and holes created by light absorption are collected in the ETL and HTL, respectively, and the electrons flow through the outer circuit and recombine with holes at the HTL/metal interface. The efficiencies of OIHP-based solar cells have increased all the way from 3.8% in 2009 to 25.5% for single-junction solar cells, and 29.15% for the highest publicly disclosed perovskite/silicon (Si) tandem [60].

The properties of perovskite solar cells were discussed in terms of crystal structure and phase transition, electronic structure, optical properties and electrical properties. One of the interesting aspect of the crystal structure of halide perovskite is the structural flexibility of organic cation. Taking MAPbI3 as an example, the disorder-order transition of MA+ cation is believed to trigger the phase transition with the decrease of temperature. At high temperature MAPbI3 takes a cubic structure (space group: Pm-3 m; Z = 1). Since MA+ has a lower symmetry of C3v, the orientation of MA+ ion should be disordered to satisfy the Oh symmetry. As the temperature is lowered, tetragonal and orthorhombic phases are realized by an accompanying ordering of methylammonium ion. Structural transition from cubic to tetragonal phase occurs due to the reorientation of MA+ ion, as observed by nuclear magnetic resonance (NMR) studies where lowering the number of disorder states of MA+ was observed from 24 in the cubic phase to 8 in tetragonal phase [61]. Below a critical temperature (tetragonal-orthorhombic phase transition), the MA+ molecule is frozen (only 1 degree of freedom) and the symmetry of MAPbI3 become orthorhombic. Similar crystallographic phase transition can be realized with replacing I by Br and Cl [62].

The band structure of MAPbI3 exhibits a direct bandgap of 1.6 eV at the R point. Calculated band structure suggests conduction band minima (CBM) is dominated by the Pb-p orbital, whereas the valence band maxima (VBM) is constituted by I-p states mixed with a small amount of Pb-s states, which is consistent with the photoemission results [63]. The optical transition of MAPbI3 relies on a direct bandgap p-p transition, leading to a strong optical absorption coefficient. Strong s-p antibonding enhances dispersion of the upper valence bands [64], which resulted in small effective masses of electrons (me*) and holes (mh*). Further, it is believed that the role of MA+ cation is to maintain the overall charge symmetry and as dictated by the crystal structure of the system [65]. However, it was reported that MA+ cation has an indirect impact on the shape and orbital composition of the band edges. The molecular orientation of MA+ cation can distort the PbI6 octahedral and affected the cell size and bonding of Pb-I, which modulated the density of states near the band edges [66]. Other halide perovskites also possess similar ways of electronic band structure.

Organic-inorganic hybrid perovskites are direct band gap semiconductor and the direct transition produces large absorption coefficients of the order of 104–105 cm−1. In the case of perovskite thin films, the optical properties of perovskites are dramatically affected by the quality, composition and morphology of the film [67]. Sizes of the halide anions (X = I, Br, Cl) affected the electronic band structure of the system. Large anion (iodine based materials) showed a smaller bandgap and corresponded the absorption edge at 780 nm; whereas substituting iodine with smaller bromine (chlorine) anion shifts the absorption edge to 535 nm (408 nm) for MA+ based perovskite system [68]. A systematic blue shift of the PL emission peak is observed with the increase of Br concentration in mixed halide perovskite of the type MAPb(I1−xBrx)3. Further, replacing MA with CH(NH2)2 red shifts the absorption spectra by 40 nm, which makes CH(NH2)2PbI3 more suitable for high-performance solar cell applications [69]. Intermediated solid solutions of MASn1−xPbxI3 with x = 0.25 and 0.5 exhibited the smallest band gap of 1.17 eV [70]. Irrespective of bandgap tuning, fundamental understanding of absorption and PL spectra are essential to study the basic photo physical properties of hybrid perovskite. In spite of several optical investigations performed at different temperatures, there have been a lot of ambiguities in the data as well as its interpretations, especially observation of multiple peaks in the photoluminescence (PL) spectrum of organic-inorganic hybrid perovskites. Literature reports excitonic emission, tetragonal inclusion in orthorhombic phase, order-disorder transition, surface-bulk effects are responsible for these multiple PL emissions [71].

Space charge limited current (SCLC) is one of the effective approaches to measure mobility, diffusion length and trap density of hybrid perovskites. Due to the advancement in fabrication techniques, the diffusion length of hybrid perovskite has increased from 1 to ~10 μm in about 3 years [72]. This improvement reflects the progress that has been recently made in producing samples with better structural order and morphology. Further, it is also observed that the diffusion length has a strong dependence on the grain size of the film. The results showed that more than 1 μm diffusion length has been achieved by realizing films with an average grain size of 2 μm. The perovskite single crystal was found the highest measured diffusion length (10 μm) [73]. Carrier mobility of hybrid perovskite has also been improved over the years and exhibited morphology dependence. Mobility values exceeding 10 cm2V−1 s−1 have been measured in perovskite film [74] and above 100 cm2V−1 s−1 in perovskite single crystals. Further, it is also observed that the mobility (and also diffusion length) did not exhibit a strong dependence on the material composition. Further, the dielectric constant (relative permittivity) is a complex number given by, ε = ε/−ε//, where the real part ε/ is the charge storage ability and the imaginary part ε// is the energyloss. For MAPbI3, a small ε/ is obtained (ε/= 6.5 in experiment, while 5.6 to 6.5 in calculation) at optical frequency and only electronic polarization takes part in dielectric process [75]. With the decrease of frequency, ionic polarization and dipolar polarization (contribution from MA+ dipoles) leading to enhanced ε//low ~ 60 at 100 KHz).This large dielectric constant facilitates the screening effect of Coulombic attraction between photoexcited electron-hole pairs (excitons), so that they can be separated easily. Also, noncentro symmetric crystal structure in tetragonal and orthorhombic phases proposed OIHP are ferroelectric in nature. It is also believed that ferroelectricity may give rise to hysteresis observed in current-voltage (I-V) curves. However, observation of ferroelectricity in hybrid perovskite is not well justified from polarization-electric field (P-E) hysteresis loop and second harmonic generation experiments. Despite the above controversies, it is of great interest to study the order-disorder transition of hybrid perovskites due to MA+ orientation inside the PbX6 octahedral [76].

Perovskite solar cell has gained attention due to favorable material properties of OIHP, which include a high absorption coefficient with a sharp absorption edge, high photoluminescence quantum yield, long charge carrier diffusion lengths, large mobility, high defect tolerance, and low surface recombination velocity. At the same time, easy solution processability and completely tunable optical bandgap from blue to red regions of wavelength just by mixing the B-site cation (Pb-Sn) and the X-site anion (I-Br-Cl), while maintaining the sharp absorption edge makes the OIHP family a potential candidate for application in multijunction/tandem solar cells. Another strong advantage of hybrid perovskite solar cells is quite high Voc, which can be explained by the suppression of the defect formation in the bulk layer as well as at the interfaces. It is observed that OIHP solar cells with Eg < 1.65 eV, the open circuit current (Voc) is remarkably high and Voc increases with band gap (Eg) without significant Voc loss. In particular, a quite high Voc of 1.26 V has been reported for a pure MAPbI3 cell, which is very close to the theoretical limit of 1.32 V, with Voc loss of only 60 mV. High absorption coefficient and low nonradiative recombination rate of OIHP solar cell resulted very small short circuit current (Jsc) loss. We know that photovoltaic devices rarely operate at room temperature, and high power output is necessary even under high-temperature operation conditions. It is observed that OIHP solar cell shows the lowest temperature coefficient (TC) of −0.17%, which is far better than other photovoltaic devices. Also nearly 90% efficiency is maintained even at a high operating temperature of 85°C. Further, OIHP-based solar cell exhibited some unique advantages such as low-temperature processes for all sub cells, compatibility with flexible and lightweight applications, low life-cycle environmental impacts and embodied energy, and potentially low fabrication costs.

Although OIHP solar cells produced quite impressive efficiency, they have several limitations too and to overcome these limitations are the major challenge for the commercialization of these devices. One significant drawback of OIHP is degradation of these perovskite materials under a range of environmental factors such as humidity, illumination, oxygen, and thermal stress. OIHP solar cells are ionic crystals, and the presence of H2O leads to the decomposition of the perovskite structures to hexagonal-shaped PbI2/hydrate crystals; which can be suppressed by introducing protective (passivation) layers. In case of mixed halide perovskites strong photo-induced phase segregation occurred under illumination and judicial choice of A-site cation can minimize this instability. Further, it is observed that a higher level of performance in OIHP solar cell is hindered by anomalous hysteretic behavior and large discrepancy between the forward and reverse scans put a question on the reproducibility of power conversion efficiency (PCE) of the device. In searching for the possible origins of hysteresis, several explanations such as ion migration, charge trapping/detrapping, photoinduced capacitive effect, and ferroelectricity have been imposed. Among them, ion migration and ferroelectricity are believed as feasible origins of the hysteresis in transport measurements. Extensive research efforts continue to find the long-term stability of OIHP solar cells.

Another major challenge is the realization of large-area module due to its fabrication limitations. Till now high efficiency of 17.9% has been realized for the large-area module with a size of 30 × 30 cm2 (aperture area: 802 cm2), which was formed by an inkjet printing technology. Thus development of proper fabrication technique is essential to make pinhole free large-area OIHP devices. Also in the large area tandem cells, current matching conditions for the top and bottom cells as well as each sub cell need to be established; which can be improved through technological advances.

High toxicity of heavy metal (lead) is a serious problem which cannot be neglected in OIHP-based solar cells. Although the content of lead (Pb) in OIHP solar panel (~1m2) is only a few hundred milligrams, could be severe problems in environmental impact. As an alternative people are trying to replace Pb2+ with Sn2+; but the efficiency of Sn-based photovoltaic devices are extremely poor. Thus, roof-top application of OIHP modules is difficult and large-area operations as solar farms are more appropriate. Also, encapsulation of photovoltaic module and environmentally friendly 100% recycling programs are essential for OIHP-based solar modules.

The future of perovskite solar cells was highlighted. As discussed earlier, the significantly reduced efficiency upon solar module area scaling-up is still the main challenge to face for the commercialization of OIHP-based solar cell. It is observed that efficiency decreases to 19.6% when the aperture area increases from 0.1 cm2 to about 10 cm2, and further drops to 17.9% with the area approaching 1000 cm2, which still lags far behind that of the crystalline silicon cells (26.7% at 79 cm2 and 24.4% at 13,177 cm2). Thus, intensive works should be conducted to precisely control the uniformity of the crystallization process in large-area perovskite films. Also, the fundamental photophysical mechanisms relative to the efficiency loss in OIHP modules should be further studied to understand role of surface and interface. Development of green solvent systems or the solvent-free deposition technology for fabricating large-area perovskite film will be an important research topic in the future. Besides the efficiency, more and more attention need to invest in the long-term stability of OIHP solar modules. Recently, Okinawa Institute of Science and Technology Graduate University in Japan reported over 1100-h operational lifetime for a 10 × 10 cm2 solar module. Although many research groups and companies claimed that their devices have passed International Electro Technical Commission (IEC) standard test, there are still some stability issues needed to be addressed at the next stage. Thus proper development of encapsulation technology is essential and we believe that a growing number of studies will move to exploit such multifunctional encapsulation materials in the near future. The single-junction OIHP cells with efficiency above 24% and long-term stability can be more cost-effective than tandem cells which may work at a PCE of 27–28%. Thus, more efforts should be made in fabrication and scaling up of single-junction OIHP-based solar cells with high efficiency, high yield, and long-term stability. Development of low-cost large-scale fabrication methods with highly reproducible results is required for commercialization of OIHP-based photovoltaic cells.


4. Thin film based sensor

A thin film-based sensor is a type of transducer which converts a physical or chemical quantity into equivalent electrical for measurement. It is used to detect the presence of stimulus to very low concentrations of toxic or harmful target environment (gases) of importance, such as ammonia [77], carbon monoxide [78], carbon dioxide [79], nitrogen dioxide [80], sulfur dioxide [81], propane [82], liquefied petroleum gas [83], hydrogen sulfide [84], and volatile organic compounds. Worldwide thin film gas sensing technology is playing a major role in protecting the environment and improving homeland security. Sensors are also critical in improving the reliability and efficiency of manufacturing operations by providing faster and more accurate feedback regarding product quality. In the area of environmental health and safety, lowering the limits of detection can improve the quality of life through precise information regarding the pollutants in air, water and soil. High-performance thin-film sensors and systems are essential to monitoring various kinds and quantities of analysts.

The typically thin film-based sensors are described using the main characteristics such as sensing response, stability, repeatability, reproducibility, linearity, response time, and recovery time. An efficient thin-film sensor;

  • Must have a high sensing response towards a very low concentration of target gas.

  • Would give the same sensing characteristics after repeated usage (stability) and for different sensors of the same kind.

  • Should be capable of responding fast towards a target gas.

  • Must regain initial characteristics as soon as the target gas is flushed.

  • Thin-film sensor response should increase linearly with increasing the concentration of target gas.

The thin film-based gas sensors are used for equally the identification and quantification of gases, and hence should be both selective and sensitive to a required target gas in a mixture of gases. Sensitivity defines the smallest concentration of gas/vapour that can be fruitfully and repeatedly sensed by a thin film sensor.

Thin film-based semiconductor is commonly used materials as sensor application as indicated in Table 1. This is because of its versatile advantages like high sensitivity and low manufacturing is metal oxide which contain the elements having one oxidation state because it requires more energy to form more than one oxidation states. Semiconductor metal oxide films have been exploited for the sensing of various toxic and harmful gases in the form of ceramics, thick films, thin films or nanostructures. Sensors based on ceramics have shown advantages in terms of their mechanical strength, large resistance to chemical attack and good thermal and physical stability and most of the available commercial sensors are based on ceramics only. One of the additional attractive features associated with low temperature operated semiconductor thin film sensor is that it can lead to a complete integration with well-established Si based micro-electronics technology.

S. No.Material/modifierTemperature (°C)Gas concentration (ppm)ResponseResponse/recovery timeReference
1.SnO2/Pt20010008920/27 sec[85]
2.ZnO/PANI361000133.3/9.8 min[86]
3.TiO2/PANI2730.1 vol%0.633.3/3.0 min[87]
5.ZnO/PEDOT: PSS2710000.583.7/3.1 min[89]
6.ZnO/MWCNT301500615.8/3 min[90]
7.h-BN/−RT3.0 vol%6.1755/40 sec[91]
8.PANI/−RT10012.1011/07 sec[92]
9.ZnO-TiO2/PANI302041235/54 sec[93]
10.CdS/−70201735.52/3.46 min[94]
11.Ag-BaTiO3/CuO25050000.2815/10 min[95]
12.CuO-CuxFe3−xO425030000.509.5/− min[96]
13.CdO25050000.013.33/5 min[97]
14.PEDOT-BPEIRT10000.03−/60 min[98]
15.La1xSrxFeO338020000.2511/15 min[99]
16.ZnO20030000.038 /40 sec[100]
17.ZnO-La (50%)40050000.6590/38 sec[101]
18.SnO2/PANI/Ag301000671000/900 sec[102]
19.TiO2/ZnRT1.5 vol%2.92120/− Sec[103]
20.Fe2O3/ PANIRT202292.35/3.8 min[104]

Table 1.

Literature survey of various gas sensing characteristics of different metal oxidebased nanomaterials with different modifiers.

The limitation of thin film based sensor was described. A number of thin film sensors might be recognized from sensor arrays which yield slightly different responses to various target gases. The availability of thin film gas sensor potentially creates a complicated selection problem, and is more important in view of cost and technology limitations. Many researchers have self-sufficiently confirmed practical limitations to thin film gas detection at low temperature and have attributed it to the requirement of high activation energy which can be attained only at elevated temperatures. A reduction in the number of sensors to be involved in E-Nose is advantageous due to several reasons as discussed. Sensors which exhibit an insignificant response to target gases, increase variance (noise) in E-Nose and do not assist pattern recognition process. Furthermore, sensors exhibiting similar responses to the target gases provide no additional information and are redundant.

In future, low temperature operation of the thin film sensors is an attractive proposition for the industry since it not only holds a promise to cut down the costs but also overcome technological limitations of miniature heaters of high wattage. In order to identify the target gases other classification technique such as artificial neural network approach is required where the selected features/variables obtained from principal component analysis (PCA) could be used as input features, and will be carried out in future. Therefore, a new methodology or novel design approach is essentially required in order to fulfil the essential requirements of future sensor in the market.


5. Metal sulphide, metal telluride and metal selenide thin film based solar cells

Metal chalcogenide materials are considered as excellent absorber materials in photovoltaic cell applications. These materials exhibited excellent absorption co-efficient and suitable band gap value to adsorb the maximum number of photons from sun radiation. Photovoltaic cell can be used to convert sunlight into electricity. These materials have a several advantages such as flexible, lower in weight, have less drag and very thin layer (from nanometer to micrometers). Preparation of the films has been reported by many researchers via different deposition methods. The properties of obtained films were studied by using various tools. The obtained experimental findings revealed that these materials could be classified into two groups, namely p-type and n-type materials. Experimental results confirmed that electron (n-type material) can absorb the energy from photons, following that, jump to the p-type materials, to produce electric potential.

Metal chalcogenide materials are considered as excellent absorber materials in photovoltaic cell applications [105, 106]. These materials exhibited excellent absorption co-efficient and suitable band gap value to adsorb the maximum number of photons from sun radiation [107, 108]. Photovoltaic cell can be used to convert sunlight into electricity. These materials have a several advantages such as flexible, lower in weight, have less drag and very thin layer (from nanometer to micrometers). Preparation of the films has been reported by many researchers via different deposition methods [109]. The properties of obtained films were studied by using various tools [110]. The obtained experimental findings revealed that these materials could be classified into two groups [111, 112], namely p-type and n-type materials. Experimental results confirmed that electron (n-type material) can absorb the energy from photons, following that, jump to the p-type materials, to produce electric potential.

Based on the global photovoltaic market [113], the market shares of silicon based solar cell decreased from 92% (in 2014) to 73.3% in 2020. Silicon based solar cell accountable for the highest percentage of market share due to the abundant raw material availability and high efficiency value. The thin film based solar cells increased from 2014 (7%) to 2020 (10.4%). Solar cell market is expected to growth rapidly due to the rising demand for commercial, residential and utility applications. According to the market share of thin film technologies [114], there are three common thin film materials such as amorphous silicon, cadmium telluride and copper indium gallium selenide. Amorphous silicon based solar cell was the oldest thin film technologies, and it dominates overall market from 2000 to 2003. This type of solar cell can absorb a wide range of the light spectrum, did excellent in low light, but loses efficiency rapidly. The CdTe films have been deposited successfully onto glass. Quaternary thin films such as copper indium gallium selenide were prepared via co-evaporation method. The global demand for CdTe films and CIGS films was expected to drive the market start from 2004 and onwards [114].

The cadmium telluride thin films could be used as solar absorber due to suitable band gap value and high absorption coefficient in the visible light region [115]. The materials have high absorption coefficient was able a low absorber thickness (about 1 μm) to absorb sufficient sunlight. Generally, several researchers reported the synthesis of CdTe films by using various deposition methods such as chemical bath deposition [116], spray pyrolysis [117], thermal evaporation [118], molecular beam epitaxy [119], close space sublimation [120], pulsed laser deposition method [121], hydrothermal method, electrochemical deposition technique. Researchers pointed out that the CdTe films deposited onto glass substrates showed some problems such as heavy and fragile. Currently, more and more research activities are focusing on the synthesis of CdTe films onto metal foils in order to lower the investment in equipment and infrastructure. The thin film deposited onto flexible substrates could be folded in any shape, and the researcher concluded that the supporting structure requirements are minimum if compared to heavy glass substrates. Table 2 showed the advantages, limitations, power conversion efficiency of CdTe films. Also, the solar power plant was described in the table. So far, the First Solar Company is the main producer of CdTe film.

AdvantagesLimitationsSolar power plantPower conversion efficiency (%)
CdTe has band gap about 1.5 eV, it can absorb sunlight at close to ideal wavelength, it captures energy at shorter wavelength.Toxic effect of cadmiumThe Topaz Solar Farm was located in California, United States. The photovoltaic power station includes 9 million CdTe thin film modules [122].19% as reported by Gloeckler and co-workers [123]
The cadmium is abundantVery limited availability of telluriumIn the Desert Sunlight Solar Farm (California, United States), it employed 8.8 million CdTe film modules [124].13.3% as highlighted by Kamala and coworkers [125]
CdTe film based solar cell showed the shortest energy payback time and the smallest carbon footprint.It does not remain stable under severe stressThe Waldpolenz Solar Park was located in Germany, has used CdTe film modules, was 52megawatt photovoltaic power station [126].15% as pointed out by Devendra and co-workers [127]
It is very important to enhance the efficiency of solar cellsTemplin solar power plant was located in Germany, has installed more than 1.5 million CdTe film modules [128].17.8% as concluded by Deb and coworkers [129]
9.59% as described by Xixing and coworkers [130]

Table 2.

Advantages, limitations, power conversion efficiencies and CdTe film based solar power plant.

The copper indium gallium selenide (CIGS) thin films have been prepared by using different deposition methods such as thermal evaporation method [131], spray pyrolysis [132], solvothermal method [133], physical vapor deposition [134], and electro deposition method [135]. Table 3 showed the advantages, limitations and power conversion efficiency of CIGS thin films. These films showed p-type absorbing layer materials and the tunable band gap (1.07–1.7 eV) value [141]. Researcher highlighted that there are 99% of the light will be successfully absorbed in the first micrometer of the materials [142]. The solar cell is classified as heterojunction structures [143]. Generally, the junction is produced between thin films having various band gap values. Experimental results showed that the addition of small amount of gallium can improve the voltage, boost band gap value and enhance the power conversion efficiency of solar cell [144]. There are several companies produced CIGS solar cell such as Solar Frontier, Solyndra, SoloPower, Global Solar, SulfurCell, MiaSole and Nanosolar. The solar cell showed open circuit voltage, short circuit current and the maximum power values of 5 V Dc, 95 mA and 0.25 watts, respectively.

AdvantagesLimitationsPower conversion efficiency (%)
CIGS thin films have been deposited onto substrates (flexible)Less efficient if compared to silicon based solar panelsConventional solar cell: 22.67%. Adding the BSF (PbS) layer in solar cell: 24.22% as reported by Barman and Kalita [136]
The active layer could be deposited in polycrystalline form.Higher production costs if compared to other thin film technologies.The highest efficiency is 25.5% as highlighted by Sobayel and coworkers [137]
Much lower level of cadmium will be used during the synthesis of thin filmsComplex structuresThe highest power conversion efficiency was 26.4% as concluded by Sobayel and co-workers [138]
CIGS thin films based solar panel indicated better resistance to heat.Boubakeur et al. have achieved power conversion efficiency of 21.08%. [139]
Much less expensive if compared to silicon based solar cells.Nour and Patane reported the highest power conversion efficacy about 24.5%. [140]

Table 3.

The advantages, limitations and power conversion efficiency of CIGS thin films.

The copper rich p-type CuInS2 films were synthesized by using thermal co-evaporation method. The obtained results showed that small (less than 10%) solar to electrical conversion losses when the copper to indium ration between 1 and 1.8. The highest power conversion efficiency was 10.2% as reported by Scheer and co-workers [145].

The chemical bath deposition was used to produce Ni3Pb2S2 thin films [146]. The photovoltaic parameters such as open circuit voltage (0.61 V), short circuit current density (9.9 mA/cm2), fill factor (0.47) and power conversion efficiency (2.7%) were studied. The band gap was calculated based on the absorption spectra and was about 1.4 eV.

The atomic layer deposition was employed to produce SnS films [147] as highlighted by Rafael and co-workers. These materials are non-toxic solar cell, and the power conversion efficiency was 4.36%. Vera and co-workers [148] reported that SnS heterojunction solar cell was made, and reached power conversion efficiency about 3.88%.

The performance of p-type InSe films for solar cell was reported. The open circuit voltage (0.55 V), short circuit current density (7.09 mA/cm2), fill factor (53.85%, and power conversion efficiency (0.52%) were highlighted. Researchers explained that higher series resistance and reduced shunt resistance lead to lower value of efficiency. The band gap values are in the range of 1.75–1.95 eV in as-deposited films, annealed films at 250 and 300°C as concluded by Teena and co-workers [149].

The electrochemical technique was used to produce CdSe film MnCdSe films as described by Shinde and co-workers [150]. XRD analysis showed the obtained films are polycrystalline with hexagonal crystal phase. The SEM images revealed that nanosphere morphology and nanonest structure for CdSe and MnCdSe films respectively. The band gap value was measured, and the reduced from 1.81 eV (CdSe) to 1.6 eV (MnCdSe). The fill factor and power conversion efficiency of CdSe films 0.71 and 0.67%, respectively. The MnCdSe films showed power conversion efficiency about 0.37%.

The ternary compound such as Cu2SnS3 (CTS) films showed high absorption coefficient (104 cm−1) and wider range of band gap energy (0.9–1.7 eV). Researchers reported that easy to control the secondary phase during the synthesis of CTS films. The formation of cubic, monoclinic, tetragonal and orthorhombic structure strongly depended on deposition method and annealing process. The magnetron sputtering method was used to produce CTS films. The films reached the highest power conversion efficiency about 2.2%, due to the formation of pure phase of CTS, lowest sheet resistance (8.2 Ω/cm2), highest shunt resistance (111.1 Ω/cm2) and uniform morphology [151]. The p-type CTS films have been produced via co-evaporation method [152]. The photovoltaic parameters such as open circuit voltage (248 mV), short circuit current density (33.5 mA/cm2), fill factor (0.439) and power conversion efficiency (3.66%) were highlighted. Mingrui and co-workers [153] described the preparation of CTS films by using sputtering method. The films prepared at 2812 seconds indicated the highest efficiency value (2.39%), with fill factor (39.7%), open circuit current voltage (208 mV) and short circuit current density (28.92 mA/cm2).

The Cu4SnS4 films showed p-type electrical conductivity and the band gap values (0.93–1.84 eV). Chen et al., have reported the synthesis of thin films by a combination of mechanochemical and doctor blade techniques [154]. The highest power conversion efficiency reached 2.34%. The influence of the film thickness on the properties of samples was study. Based on the absorption spectra, the absorption edge moved towards longer wavelength with increasing the film thickness (0.25–1 μm). Also, band gap reduced (1.47–1.21 eV) due to reduction of structural disorder and the increase in the crystalline size.

The Table 4 showed the power conversion efficiency of the various thin films. The obtained experimental results confirmed that metal sulfide, metal selenide and metal telluride thin films could be used in solar cell applications. The photovoltaic parameters were strongly depended on various experimental conditions. Researchers also highlighted a lot of research activities have been carried put in order to enhance the power conversion efficiency of thin film based solar cell.

thin filmsPower conversion efficiency (%)References
Cu2ZnSnS45.74Kazuo and co-workers [155]
Cu2ZnSnS42.62Hironori and co-workers [156]
Cu2ZnSnS46.8Wang and co-workers [157]
Cu2ZnSnS44.1Schubert and co-workers [158]
Cu2ZnSnS40.23Chet and co-workers [159]
Cu2ZnSnS43.2Jonathan and co-workers [160]
Cu2ZnSnS43.4Ennaoui and co-workers [161]
Cu2ZnSnS40.396Sawanta and co-workers [162]
Cu2ZnSnS46.03Tsukasa and co-workers [163]
Cu2ZnSnS40.12Shinde and co-workers [164]
CuS0.39Donghyeok and co-workers [165]
CdS8Karl [166]
ZnS8.83Qiu and co-workers [167]
PbS2.02Omer and co-workers [168]
PbS:Mo2.16Omer and co-workers [168]
Sb2Se37.6Wen and co-workers [169]
Sb2Se35.93Liang and co-workers [170]
Sb2Se35.6Chao and co-workers [171]
CuInTe23.8Manorama and co-workers [172]
CuInTe24.13Lakhe and co-workers [173]
CuInTe21.22Jia and co-workers [174]
CuInSe21.75Hyun and co-workers [175]
CuInSe22Se and co-workers [176]
CuInSe24.57Prabukanthan and co-workers [177]
MnCuInSe26.38Prabukanthan and co-workers [177]

Table 4.

Power conversion efficiencies of different types of thin films.


6. Conclusions

Chalcogenide thin films have received a great deal of attention for decades due to some unique properties. The thin film based supercapacitor can have store the electrical energy for all the electronic devices to stabilize the power supply. Metal nitrates have gotten a lot of interest as supercapacitors electrodes due to showed higher electrical conductivity, higher specific capacitance, good energy density, and excellent mechanical stability. Perovskite solar cell indicated higher power conversion efficiency value. The organic inorganic hybrid perovskite solar cells are very simple, and prepared by sandwiching a perovskite absorber layer between the electron transport layer and hole transport layer, reached power conversion efficiency exceeding 20%. The thin film-based sensors showed high sensitivity and low manufacturing cost. In future, low temperature operation of the thin film sensors is an attractive proposition for the industry. The market shares of silicon based solar cell decreased, while thin film based solar cells increased in the global photovoltaic market due to the low material consumption, low manufacturing cost, shorter energy pack back period. Solar cell market is expected to growth rapidly due to the rising demand for commercial, residential and utility applications.



The author (HO SM) gratefully acknowledge the financial support provided by the INTI International University.


Conflict of interest

The authors declare no conflict of interest.


  1. 1. Xing C, Lei Y, Liu M, Wu S, He W. Environment-friendly Cu-based thin film solar cells: materials, devices and charge carrier dynamics. Physical Chemistry Chemical Physics. 2021;23:16469-16487
  2. 2. Kassim A, Saravanan N, Ho SM, Lim K. SEM, EDAX and UV-visible studies on the properties of Cu2S thin films. Chalcogenide Letters. 2011;8:405-410
  3. 3. Ngai CF, Anuar K, Ho SM, Tan W. Influence of triethanolamine on the chemical bath deposited NiS thin films. American Journal of Applied Sciences. 2011;8:359-361
  4. 4. Faiz R. Zinc oxide light emitting diodes: A review. Optical Engineering. 2019;58. DOI: 10.1117/1.OE.58.1.010901
  5. 5. Ho SM. Influence of complexing agent on the growth of chemically deposited Ni3Pb2S2 thin films. Oriental Journal of Chemistry. 2014;30:1009-1012
  6. 6. Atan S, Ho SM, Anuar K, Saravanan N. Effect of deposition period and pH on chemical bath deposited Cu4SnS4 thin films. Philippine Journal of Science. 2009;138:161-168
  7. 7. Jesu A, Najla A, Khan A, Mohd S, Algarni H. High sensitive samarium-doped ZnS thin films for photo-detector applications. Optical Materials. 2021;122. DOI: 10.1016/j.optmat.2021.111649
  8. 8. Tan WT, Ho SM, Anuar K. Composition, morphology and optical characterization of chemical bath deposited ZnSe thin films. European Journal of Applied Sciences. 2011;3:75-80
  9. 9. Shinde K, Dhaygude D, Fulari V, Chikode P. Structural, morphological, optical and hologram recording of the CdS and ZnS thin films by double exposure digital holographic interferometry technique. Journal of Materials Science: Materials in Electronics. 2017;28:7385-7392
  10. 10. Ramos M, Lopez J, Rascon J, Reyes D, Flores P. Structural and optical modifications of CdS properties in CdS-Au thin films prepared by CBD. Results in Physics. 2021;22. DOI: 10.1016/j.rinp.2021.103914
  11. 11. Teo D, Anuar K, Saravanan N, Ho SM, Tan W. Chemical bath deposition of nickel sulphide (Ni4S3) thin films. Leonardo Journal of Sciences. 2010;16:1-12
  12. 12. Jelas M, Anuar K, Ho SM, Tan W, Gwee SY. Effects of Deposition Period on the Properties of FeS2 Thin Films by Chemical Bath Deposition Method. Thammasat International Journal of Science and Technology. 2010;15:62-69
  13. 13. Anuar K, Ho SM, Saravanan N, Noraini K. XRD and AFM studies of ZnS thin films produced by electro deposition method. Arabian Journal of Chemistry. 2010;3:243-249
  14. 14. Atef S, Sayed M. Electrodeposition, characterization and photo electrochemical properties of CdSe and CdTe. Ain Shams Engineering Journal. 2014;6:341-346
  15. 15. Tuyen T, Sudam C, Ivet K, Oscar M, Ramon T. Electrodeposition of antimony selenide thin films and application in semiconductor sensitized solar cells. ACS Applied Materials & Interfaces. 2014;6:2836-2841
  16. 16. Sreeja V, Sabitha P, Anila E, Radhakrishnan P. Nonlinear optical characterization of ZnS thin film synthesized by chemical spray pyrolysis method. AIP Conference Proceedings. 2015;1620. DOI: 10.1063/1.4898292
  17. 17. Mahalingam T, Lee S, Kim Y, Moon S, Kathalingam A. Studies of electro synthesized zinc selenide thin films. Journal of New Materials for Electrochemical Systems. 2007;10:15-19
  18. 18. Fida M, Tahir M, Zeb M, Ali S, Sabri M, Sarker R. Synergistic enhancement in the microelectronic properties of poly-(dioctylfluorene) based Schottky devices by CdSe quantum dots. Scientific Reports. 2020;10. DOI: 10.1038/s41598-020-61602-1
  19. 19. Seok Y, Seo W, Lee S, Shim W. Preparation of CuInSe2 thin films through metal organic chemical vapor deposition method by using di-μ-methylselenobis(dimethylindium) and bis(ethylisobutyrylacetato) copper(II) precursors. Thin Solid Films. 2006;515:1544-1547
  20. 20. Marianna K, Mikko R, Markku L. Thin Film Deposition Methods for CuInSe 2 Solar Cells. Critical Reviews in Solid State and Materials Sciences. 2007;30. DOI: 10.1080/10408430590918341
  21. 21. Azhar K, Sabah H, Khalaf K. The effects of sputtering time on Cds thin film solar cell deposited by DC plasma sputtering method. Engineering and Technology Journal. 2018;36. DOI: 10.30684/etj.36.2C.5
  22. 22. Oday A, Jafar R, Adnan M, Nadir F, Chiad S. Synthesize of CdS and CdS: V films via spray pyrolysis technique: Morphology and optical properties. Design Engineering. 2020;5:356-365
  23. 23. Atan S, Ho SM, Kassim A, Nagalingam S. X-ray diffraction and atomic force microscopy studies of chemical bath deposited FeS thin films. Studia Universitatis Babes-Bolyai Chemia. 2010;55:5-11
  24. 24. Ho SM, Anuar K. Deposition and characterization of MnS thin films by chemical bath deposition method. International Journal of Chemistry Research. 2010;1:1-5
  25. 25. Sharif S, Khuram S, Saeed A, Rana F, Azad M. In situ synthesis and deposition of un-doped and doped magnesium sulfide thin films by green technique. Optik. 2019;182:739-744
  26. 26. Okoli D. Optical properties of chemical bath deposited magnesium sulphide thin films. Chemistry and Materials Research. 2015;7:61-67
  27. 27. Rasaq A, Kola R, Adeniyi T, Talabi T. Synthesis and characterization of ZnSe thin films deposited by thermal vacuum evaporation method for photovoltaic application. Applied Journal of Environmental Engineering Science. 2020;6:227-237
  28. 28. Anuar K, Ho SM, Noraini K, Saravanan N. XRD and AFM studies of ZnS thin films produced by electrodeposition method. Arabian Journal of Chemistry. 2010;3:243-249
  29. 29. Ghezali K, Mentar L, Azizi A, Boudine B. Electrochemical deposition of ZnS thin films and their structural, morphological and optical properties. Journal of Electroanalytical Chemistry. 2017;794:212-220
  30. 30. Patil S, Fulari J, Lohar M. Structural, morphological, optical and photoelectrochemical cell properties of copper oxide using modified SILAR method. Journal of Materials Science: Materials in Electronics. 2016;27:9550-9557
  31. 31. Lee W, Wang X. Structural, Optical, and Electrical Properties of Copper Oxide Films Grown by the SILAR Method with Post-Annealing. Coatings. 2021;11. DOI: 10.3390/coatings11070864
  32. 32. Ho SM. Properties study of SILAR deposited cobalt selenide thin films. International Journal of Research and Review. 2021;8. DOI: 10.52403/ijrr.20211216
  33. 33. Chavan T, Yadav A, Kamble S, Sabah A, Insik I, Cho E, et al. Electrochemical supercapacitive studies of chemically deposited Co1-xNixS thin films. Materials Science in Semiconductor Processing. 2020;107. DOI: 10.1016/j.mssp.2019.104799
  34. 34. Zhao J, Tian Y, Liu A, Zhao Z, Song L. The NiO electrode materials in electrochemical capacitor: A review. Materials Science in Semiconductor Processing. 2019;96:78-90
  35. 35. Wiston B, Ashok M. Microwave-assisted synthesis of cobalt-manganese oxide for supercapacitor electrodes. Materials Science in Semiconductor Processing. 2019;103. DOI: 10.1016/j.mssp.2019.104607
  36. 36. Sarkar S, Howli P, Das B, Das N, Samanta M. Novel quaternary chalcogenide/reduced graphene oxide-based asymmetric supercapacitor with high energy density. ACS Applied Materials Interfaces. 2019;9:22652-22664
  37. 37. Velanganni S, Pravinraj S, Immanuel P. Nanostructure CdS/ZnO heterojunction configuration for photocatalytic degradation of Methylene blue. Physica B: Condensed Matter. 2018;534:56-62
  38. 38. Zahirullah S, Immanuel P, Pravinraj S, Inbaraj H, Joseph J. Synthesis and characterization of Bi doped ZnO thin films using SILAR method for ethanol sensor. Materials Letters. 2018;230:1-4
  39. 39. Immanuel P, Prakash A, Raja M. Ethanol sensing of V2O5 thin film prepared by spray pyrolysis technique: Effect of substrate to nozzle distance. AIP Conference Proceedings. 2017;1832. DOI: 10.1063/1.4980482
  40. 40. Immanuel P, Mohan R. Effect of process temperature on the preparation of V2O5 thin films by spray pyrolysis method for ethanol sensing application. Materials Focus. 2016;5:362-367
  41. 41. Dai C, Chien P, Lin Y, Chou W, Li P, Lin T. Hierarchically structured Ni3S2/carbon nanotube composites as high performance cathode materials for asymmetric supercapacitors. ACS Applied Materials Interfaces. 2013;5:12168-12174
  42. 42. Xiao Y, Fang S, Su D, Wang X, Zhou L, Wu S, et al. In suit growth of ultra-dispersed NiCo2S4 nanoparticles on graphene for asymmetric supercapacitors. Electrochimica Acta. 2015;176:44-50
  43. 43. Mukkabla R, Deepa M, Kumar S. Poly(3,4-ethylenedioxypyrrole) Enwrapped Bi2S3 Nanoflowers for Rigid and Flexible Supercapacitors. Electrochimica Acta. 2015;164:171-181
  44. 44. Balogun M, Zeng Y, Luo Y, Qiu W, Titus K, Tong Y. Three-dimensional nickel nitride (Ni3N) nanosheets: free standing and flexible electrodes for lithium ion batteries and supercapacitors. Journal of Materials Chemistry A. 2016;4:9844-9849
  45. 45. Vivek E, Arulraj A, Khalid M, Vetha P. Facile synthesis of 2D Ni(OH)2 anchored g-C3N4 as electrode material for high-performance supercapacitor. Inorganic Chemistry Communications. 2012;130. DOI: 10.1016/j.inoche.2021.108704a
  46. 46. Arulraj A, Mehana U, Ramesh M, Raj A. Metal chalcogenides as counter electrode materials. In: Alagarsamy P, Mohan R, Kandasamy J, editors. Counter Electrode for Dye-Sensitized Solar Cells. 1st ed. New York: Jenny Stanford Publishing; 2021. pp. 126-156. DOI: 10.1201/9781003110774
  47. 47. Krishnan G, Arulraj A, Priyanka J, Khalid M. 2D materials for supercapacitor and supercapattery applications. In: Singh L, Durga M, editors. Adapting 2D Nanomaterials for Advanced Application. Washington DC: ACS Publication; 2020. pp. 33-47. DOI: 10.1021/bk-2020-1353
  48. 48. Krishnan S, Arulraj A, Khalid M, Reddy M. Energy storage in metal cobaltite electrodes: Opportunities & challenges in magnesium cobalt oxide. Renewable and Sustainable Energy Reviews. 2021;141. DOI: 10.1016/j.rser.2021.110798
  49. 49. Guo Y, Hong F, Wang Y, Li Q, Dai R, Meng J, et al. Multicomponent hierarchical Cu-doped NiCo-LDH/CuO double arrays for ultralong-life hybrid fiber supercapacitor. Advanced Functional Materials. 2019;29. DOI: 10.1002/adfm.201809004
  50. 50. Zhang Y, Hu Y, Wang Z, Zhu X, Luo B, Han H, et al. Lithiation-Induced Vacancy Engineering of Co3O4 with Improved Faradic Reactivity for High-Performance Supercapacitor. Advanced Functional Materials. 2020;30. DOI: 10.1002/adfm.202004172
  51. 51. Bandgar B, Vadiyar M, Ling Y, Chang J, Han S, Anil V. Metal precursor dependent synthesis of NiFe2O4 thin films for high-performance flexible symmetric supercapacitor. ACS Applied Energy Materials. 2018;1:638-648
  52. 52. Immanuel P, Chang H, Mohanraj K, Kumar S. Effect of Cr doping on Mn3O4 thin films for high-performance supercapacitors. Journal of Materials Science: Materials in Electronics. 2021;32:3732-3742
  53. 53. Jesuraj S, Haris M, Immanuel P. Structural and optical properties of pure Nio and Li-doped nickel oxide thin films by sol-gel spin coating method. International Journal of Science and Research. 2013;8:85-87
  54. 54. Kim Y, Shin K. Dopamine-assisted chemical vapour deposition of polypyrrole on graphene for flexible supercapacitor. Applied Surface Science. 2021;547. DOI: 10.1016/j.apsusc.2021.149141
  55. 55. Yu S, Xiong X, Jun M, Qian H. One-step preparation of cobalt nickel oxide hydroxide @cobalt sulfide heterostructure film on Ni foam through hydrothermal electrodeposition for supercapacitors. Surface and Coatings Technology. 2021;426. DOI: 10.1016/j.surfcoat.2021.127791
  56. 56. Immanuel P, Mohanraj K, Senguttuvan G. Enhanced activity of chemically synthesized nanorod Mn3O4 thin films for high performance supercapacitors. International Journal of Thin Film Science and Technology. 2020;9:57-67
  57. 57. Vivek E, Arulraj A, Syam G, Vetha P, Khalid M. Novel nanostructured Nd(OH)3/g-C3N4 nanocomposites (nanorolls anchored on nanosheets) as reliable electrode material for supercapacitors. Energy & Fuels. 2021;35:15205-15212
  58. 58. Arulraj A, Ramesh M, Rajeshkumar V, Ilayaraja N. Direct synthesis of cubic shaped Ag2S on Ni mesh as binder-free electrodes for energy storage applications. Scientific Reports. 2019;9. DOI: 10.1038/s41598-019-46583-0
  59. 59. Moller C. Crystal structure and photoconductivity of cæsium plumbohalides. Nature. 1958;182. DOI: 10.1038/1821436a0
  60. 60. Kim Y, Lee J, Jung S, Shin H, Park N. High-efficiency perovskite solar cells. Chemical Reviews. 2020;120:7867-7918
  61. 61. Nandi P, Giri C, Manju U, Rath S, Topwal D. CH3NH3PbI3, a potential solar cell candidate: Structural and spectroscopic investigations. The Journal of Physical Chemistry A. 2016;120:9732-9739
  62. 62. Nandi P, Mahana S, Welter E, Topwal D. Probing the role of local structure in driving the stability of halide perovskites CH3NH3PbX3. The Journal of Physical Chemistry C. 2021;125:24655-24662
  63. 63. Nandi P, Pandey K, Giri C, Vijay S, Manju U, Mahanti D, et al. Probing the electronic structure of hybrid perovskites in the orientationally disordered cubic phase. The Journal of Physical Chemistry Letters. 2020;11:5719-5727
  64. 64. Menendez E, Palacios P, Wahnon P, Conesa C. Self-consistent relativistic band structure of the CH3NH3PbI3 perovskite. Physical Review B. 2014;90. DOI: 10.1103/PhysRevB.90.045207
  65. 65. Xiao Z, Yan Y. Progress in theoretical study of metal halide perovskite solar cell materials. Advanced Energy Materials. 2017;7. DOI: 10.1002/aenm.201701136
  66. 66. Motta C, Fedwa E, Kais S, Tabet N, Fahhad A, Sanvito S. Revealing the role of organic cations in hybrid halide perovskite CH3NH3PbI3. Nature Communications. 2015;6. DOI: 10.1038/ncomms8026
  67. 67. Li Y, Ji L, Liu R, Zhang C, Mak C, Zou X, et al. A review on morphology engineering for highly efficient and stable hybrid perovskite solar cells. Journal of Materials Chemistry A. 2018;6:12842-12875
  68. 68. Nandi P, Giri C, Topwal D. Understanding the origin of broad-band emission in CH3NH3PbBr3. Journal of Materials Chemistry C. 2021;9:2793-2800
  69. 69. Nandi P, Li Z, Kim Y, Ahn T, Park N, Shin H. Stabilizing mixed halide lead perovskites against photoinduced phase segregation by A-site cation alloying. ACS Energy Letters. 2021;6:837-847
  70. 70. Ogomi Y, Kenji Y, Pandey S, Shuzi H, Ma T, Syota T, et al. CH3NH3SnxPb(1−x)I3 perovskite solar cells covering up to 1060 nm. The Journal of physical Chemistry Letters. 2014;5:1004-1011
  71. 71. Sarkar S, Priya M. Role of the A-site cation in determining the properties of the hybrid perovskite CH3NH3Pb. Physical Review B. 2017;95. DOI: 10.1103/PhysRevB.95.214118
  72. 72. Xing G, Mathews N, Sun S, Lim S, Lam M, Sum T, et al. Long-range balanced electron- and hole-transport lengths in organic-inorganic CH3NH3PbI3. Science. 2013;342:344-347
  73. 73. Zhumekenov A, Makhsud I, Azinul M, Erkki A, Omar F, Bakr O. Formamidinium lead halide perovskite crystals with unprecedented long carrier dynamics and diffusion length. ACS Energy Letters. 2016;1:32-37
  74. 74. Wehrenfennig C, Liu M, Henry J, Johnson M, Laura M. Charge carrier recombination channels in the low-temperature phase of organic-inorganic lead halide perovskite thin films. AIP APL Materials. 2014;2. DOI: 10.1063/1.4891595
  75. 75. Govinda S, Kore P, Swain D, Akmal H, De C, Tayur N, et al. Critical comparison of FAPbX3 and MAPbX3 (X = Br and Cl): How do they differ. The Journal of Physical Chemistry C. 2018;122:13758-13766
  76. 76. Nandi P, Dinesh T, Park N, Shin H. Organic-inorganic hybrid lead halides as absorbers in perovskite solar cells: a debate on ferroelectricity. Journal of Physics D: Applied Physics. 2020;53. DOI: 10.1088/1361-6463/abb047
  77. 77. Waikar M, Raste P, Sonker K, Gupta V, Tomar M, Shirsat D. Enhancement in NH3 sensing performance of ZnO thin-film via gamma-irradiation. Journal of Alloys and Compounds. 2020;830. DOI: 10.1016/j.jallcom.2020.154641
  78. 78. Liu H, Yu H, Wang J, Xia F, Wang C, Xiao J. LaNbO4 as an electrode material for mixed-potential CO gas sensors. Sensors and Actuators B: Chemical. 2022;352. DOI: 10.1016/j.snb.2021.130981
  79. 79. Sonker R, Yadav B, Sabhajeet S. TiO2–PANI nanocomposite thin film prepared by spin coating technique working as room temperature CO2 gas sensing. Journal of Materials Science: Materials in Electronics. 2016;27:11726-11732
  80. 80. Sonker K, Yadav C, Gupta V, Tomar M, Sharma A. Experimental investigations on NO2 sensing of pure ZnO and PANI–ZnO composite thin films. RSC Advances. 2016;6:56149-56158
  81. 81. Tyagi P, Tomar M, Vinay G, Anjali S. A comparative study of RGO-SnO2 and MWCNT-SnO2 nanocomposites based SO2 gas sensors. Sensors and Actuators B: Chemical. 2017;248:980-986
  82. 82. Mousavi H, Yadollah M, Ali A, Saberi H. Enourmous enhancement of Pt/SnO2 sensors response and selectivity by their reduction to CO in automotive exhaust gas pollutants including CO, NOx and C3H8. Applied Surface Science. 2021;546. DOI: 10.1016/j.apsusc.2021.149120
  83. 83. Sabhajeet S, Yadav C, Sonker R. Sol-gel formed spherical nanostructured titania based liquefied petroleum gas sensor. AIP Conference Proceedings. 2018;1953. DOI: 10.1063/1.5032413
  84. 84. Chowdhuri A, Kumar S, Vinay G, Sreenivas K. Contribution of adsorbed oxygen and interfacial space charge for enhanced response of SnO2 sensors having CuO catalyst for H2S gas. Sensors and Actuators B: Chemical. 2010;145:155-166
  85. 85. Sonker RK, Yadav BC. Chemical route deposited SnO2, SnO2-Pt and SnO2-Pd thin films for LPG detection. Advanced Science Letters. 2014;20:1023-1027
  86. 86. Patil PT, Anwane RS, Kondawar SB. Development of electrospun polyaniline/ZnO composite nanofibers for LPG sensing. Procedia Materials Science. 2015;10:195-204
  87. 87. Dhawale DS, Salunkhe R, Patil UM, Gurav KV, More AM, Lokhande CD. Room temperature liquefied petroleum gas (LPG) sensor based on p-polyaniline/n-TiO2 heterojunction. Sensors and Actuators B: Chemical. 2008;134:988-992
  88. 88. Patil LA, Suryawanshi DN, Pathan IG, Patil DM. 2013. Nickel doped spray pyrolyzed nanostructured TiO2 thin films for LPG gas sensing. Sensors and Actuators B: Chemical. 2013;176:514-521
  89. 89. Ladhe RD, Gurav KV, Pawar SM, Kim JH, Sankapal BR. p-PEDOT: PSS as a heterojunction partner with n-ZnO for detection of LPG at room temperature. Journal of Alloys and Compounds. 2012;515:80-85
  90. 90. Sonker RK, Singh M, Kumar U, Yadav BC. MWCNT doped ZnO nanocomposite thin film as LPG sensing. Journal of Inorganic and Organometallic Polymers and Materials. 2016;26:1434-1440
  91. 91. Gautam C, Tiwary CS, Machado LD, Jose S, Ozden S, Biradar S, et al. Synthesis and porous h-BN 3D architectures for effective humidity and gas sensors. RSC Advances. 2016;6:87888-87896
  92. 92. Sonker RK, Yadav BC, Dzhardimalieva GI. Preparation and properties of nanostructured PANI thin film and its application as low temperature NO2 sensor. Journal of Inorganic and Organometallic Polymers and Materials. 2016;26:1428-1433
  93. 93. Sonker R, Yadav B, Gupta V, Tomar M. Fabrication and characterization of ZnO-TiO2-PANI (ZTP) micro/nanoballs for the detection of flammable and toxic gases. Journal of Hazardous Materials. 2019;370:126-137
  94. 94. Sonker R, Yadav B, Gupta V, Tomar M. Synthesis of CdS nanoparticle by sol-gel method as low temperature NO2 sensor. Materials Chemistry and Physics. 2020;239. DOI: 10.1016/j.matchemphys.2019.121975
  95. 95. Herrán J, Mandayo GG, Ayerdi I, Castano E. Influence of silver as an additive on BaTiO3–CuO thin film for CO2 monitoring. Sensors and Actuators B: Chemical. 2008;129:386-390
  96. 96. Chapelle A, Oudrhiri-Hassani F, Presmanes L, Barnabé A, Tailhades P. CO2 sensing properties of semiconducting copper oxide and spinel ferrite nanocomposite thin film. Applied Surface Science. 2010;256:4715-4719
  97. 97. Krishnakumar T, Jayaprakash R, Prakash T, Sathyaraj D, Donato N. CdO-based nanostructures as novel CO2 gas sensors. Nanotechnology. 2011;22. DOI: 10.1088/0957-4484/22/32/325501
  98. 98. Chiang CJ, Tsai K, Lee Y, Lin H, Yang Y, Shih C, et al. In situ fabrication of conducting polymer composite film as a chemical resistive CO2 gas sensor. Microelectronic Engineering. 2013;111:409-415
  99. 99. Fan K, Qin H, Wang L, Ju L, Hu J. CO2 gas sensors based on La1− xSrxFeO3 nanocrystalline powders. Sensors and Actuators B: Chemical. 2013;177:265-269
  100. 100. Habib M, Hussain SS, Riaz S, Naseem S. Preparation and characterization of ZnO nanowires and their applications in CO2 gas sensors. Materials Today: Proceedings. 2015;2:5714-5719
  101. 101. Jeong YJ, Balamurugan C, Lee DW. Enhanced CO2 gas-sensing performance of ZnO nanopowder by La loaded during simple hydrothermal method. Sensors and Actuators B: Chemical. 2016;229:288-296
  102. 102. Sonker R, Sabhajeet S, Yadav B, Johari R. Liquefied petroleum gas detection using SnO2, PANI-SnO2 and Ag-SnO2 composite film fabricated by chemical route. International Journal of Electroactive Materials. 2017;5:6-12
  103. 103. Sabhajeet S, Sonker R, Yadav B. Zn-Doped TiO2 nanoparticles employed as room temperature liquefied petroleum gas sensor. Advanced Science, Engineering and Medicine. 2018;10:736-740
  104. 104. Sonker R, Yadav B. Development of Fe2O3–PANI nanocomposite thin film based sensor for NO2 detection. Journal of the Taiwan Institute of Chemical Engineers. 2017;77:276-281
  105. 105. Choi Y, Park H, Lee N, Kim B, Lee J, Lee G, et al. Deposition of the tin sulfide thin films using ALD and a vacuum annealing process for tuning the phase transition. Journal of Alloys and Compounds. 2022;896. DOI: 10.1016/j.jallcom.2021.162806
  106. 106. Alireza G, Sanaz M, Mahdi A, Narges S. Study of optical properties of ZnS and MnZnS (ZnS/MnS) nanostructure thin films; Prepared by microwave-assisted chemical bath deposition method. Materials Chemistry and Physics. 2022;275. DOI: 10.1016/j.matchemphys.2021.125103
  107. 107. Chate P, Lakde S, Sathe D. Structural, optical and thermoelectric studies on chemically synthesized annealed antimony sulphide thin films. Optik. 2022;250. DOI: 10.1016/j.ijleo.2021.168296
  108. 108. Deepika G, Vishnu C, Sonica U, Singh F, Kumar S, Aman M, et al. Defects engineering and enhancement in optical and structural properties of 2D-MoS2 thin films by high energy ion beam irradiation. Materials Chemistry and Physics. 2022;276. DOI: 10.1016/j.matchemphys.2021.125422
  109. 109. Jrad A, Manel N, Ammar S, Najoua T. Chemical composition, structural, morphological, optical and luminescence properties of chemical bath deposited Fe:ZnS thin films. Optical Materials. 2022;123. DOI: 10.1016/j.optmat.2021.111851
  110. 110. Jako S, Kaia T, Oja A, Malle K. Sb2S3 thin films by ultrasonic spray pyrolysis of antimony ethyl xanthate. Materials Science in Semiconductor Processing. 2022;137. DOI: 10.1016/j.mssp.2021.106209
  111. 111. Rohini M, Oscar G, Ana R, Nair K, Santana E. Thin films of p-SnS and n-Sn2S3 for solar cells produced by thermal processing of chemically deposited SnS. Journal of Alloys and Compounds. 2022;892. DOI: 10.1016/j.jallcom.2021.162036
  112. 112. Kuang N, Zuo Z, Liu R, Zhao Z. Optimized thermoelectric properties and geometry parameters of annular thin-film thermoelectric generators using n-type Bi2Te2.7Se0.3 and p-type Bi0.5Sb1.5Te3 thin films for energy harvesting. Sensors and Actuators A: Physical. 2021;332. DOI: 10.1016/j.sna.2021.113030
  113. 113. Shahariar M, Kazi S, Tanjia C, Kuaanan T, Sieh K. An overview of solar photovoltaic panels’ end-of-life material recycling. Energy Strategy Reviews. 2020;27. DOI: 10.1016/j.esr.2019.100431
  114. 114. Kelly P. What is thin-film solar? 30 July 2018. Available from: [Accessed: December 15, 2021]
  115. 115. Jun W, Mu Y, Qian L, Yang H, Liu T, Fu W. Fabrication of CdTe thin films grown by the two-step electrodeposition technique on Ni foils. Journal of Alloys and Compounds. 2015;636:97-101
  116. 116. Deivanayaki S, Ponnuswamy V, Mariappan R, Jayamurugan P. Optical and structural characterization of CdTe thin films by chemical bath deposition technique. Chalcogenide Letters. 2010;7:159-163
  117. 117. Nikale M, Shinde S, Bhosale H, Rajpure K. Physical properties of spray deposited CdTe thin films: PEC performance. Journal of Semiconductors. 2011;32. DOI: 10.1088/1674-4926/32/3/033001
  118. 118. Tursun A, Joel N, Zheng X, Helio M, John M, Steven W, et al. Thin-film solar cells with 19% efficiency by thermal evaporation of CdSe and CdTe. ACS Energy Letters. 2020;5:892-896
  119. 119. Mikhaylov V, Polyak E. Mass-spectrometry investigation of the kinetics of the molecular-beam epitaxy of CdTe. Journal of Surface Investigation: X-Ray, Synchrotron and Neutron Techniques. 2021;15:683-695
  120. 120. Velu R, Shankar B, Nair S, Shanmugam M. Effects of gas-phase and wet-chemical surface treatments on substrates induced vertical, valley–hill & micro-granular growth morphologies of close space sublimated CdTe films. Nanoscale Advances. 2020;2:4757-4769
  121. 121. Flores M, Puente C, Galvan G, Guillen A. CdTe thin films grown by pulsed laser deposition using powder as target: Effect of substrate temperature. Journal of Crystal Growth. 2014;386:27-31
  122. 122. Topaz Solar Farm, From Wikipedia. Available from: [Accessed: December 15, 2021]
  123. 123. Gloeckler M, Zhao Z, Saknkin I. CdTe Solar Cells at the Threshold to 20% Efficiency. IEEE Journal of Photovoltaics. 2013;3:1389-1393
  124. 124. Desert Sunlight Solar Farm, from Wikipedia. Available from: [Accessed: December 15, 2021]
  125. 125. Kamala K, Ebin B, Indra S, Bista S, Rijal S, Manoj K. Semi-transparent p-type barium copper sulfide as a back contact interface layer for cadmium telluride solar cells. Solar Energy Materials and Solar Cells. 2020;218. DOI: 10.1016/j.solmat.2020.110764
  126. 126. Waldpolenz Solar Park. From Wikipedia. Available from: [Accessed: December 15, 2021]
  127. 127. Devendra K, Deb K, Yang B, Kim Y, Pant B, Park M. Numerical investigation of graphene as a back surface field layer on the performance of cadmium telluride solar cell. Molecules. 2021;26. DOI: 10.3390/molecules26113275
  128. 128. Templin Solar Photovoltaic Power plant, Brandemburg. Available from: [accessed: December 14, 2021]
  129. 129. Deb K, Amer M, Akhtar M, Devendra K. Impact of different antireflection layers on cadmium telluride (CdTe) solar cells: a PC1D simulation study. Journal of Electronic Materials. 2021;50:2199-2205
  130. 130. Xixing W, Lu T, Morris W, Wang G, Bhat I, Jian S. Epitaxial CdTe thin films on mica by vapor transport deposition for flexible solar cells. ACS Applied Energy Materials. 2020;3:4589-4599
  131. 131. Alamri N, Alsadi M. Growth of Cu(In,Ga)Se2 thin films by a novel single flash thermal evaporation source. Journal of Taibah University for Science. 2020;14:38-43
  132. 132. Kotbi A, Fadili S, Ridah A, Thevenin P, Hartiti B. Synthesis and characterization of sprayed CIGS thin films for photovoltaic application. Materials Today Proceedings. 2020;24:66-70
  133. 133. Ying L, Kong D, Li J, Zhao C, Chen C. Preparation of Cu(In,Ga)Se2 thin film by solvothermal and spin-coating process. Energy Procedia. 2012;16:217-222
  134. 134. Negami T, Takuya S, Yasuhiro H, Hayashi S. Large-area CIGS absorbers prepared by physical vapor deposition. Solar Energy Materials and Solar Cells. 2001;67:1-9
  135. 135. Lee C. CIGS Thin Film Solar Cells by Electrodeposition. Journal of the Korean Electrochemical Society. 2011;14:61-70
  136. 136. Barman B, Kalita P. Influence of back surface field layer on enhancing the efficiency of CIGS solar cell. Solar Energy. 2021;216:329-337
  137. 137. Sobayel M, Hossain T, Rashid M, Techato K, Islam S. Efficiency enhancement of CIGS solar cell by cubic silicon carbide as prospective buffer layer. Solar Energy. 2021;224:271-278
  138. 138. Sobayel K, Sopian K, Hasan M, Amin N, Karim R, Dar M, et al. Efficiency enhancement of CIGS solar cell by WS2 as window layer through numerical modelling tool. Solar Energy. 2020;207:479-485
  139. 139. Boubakeur M, Aissat A, Vilcot P, Arbia B, Maaref H. Enhancement of the efficiency of ultra-thin CIGS/Si structure for solar cell applications. Superlattices and Microstructures. 2020;138. DOI: 10.1016/j.spmi.2019.106377
  140. 140. Nour E, Patane S. Single junction-based thin-film CIGS solar cells optimization with efficiencies approaching 24.5%. Optik. 2020;218. DOI: 10.1016/j.ijleo.2020.165240
  141. 141. Bhattacharya N, Batchelor W. Thin-film CuIn1−xGa𝑥Se2 photovoltaic cells from solution-based precursor layers. Applied Physics Letters. 1999;75. DOI: 10.1063/1.124716
  142. 142. Sale of CIGS solar cell panels expected to reach S1 billion by 2013. Available from: [Accessed: December 12, 2021]
  143. 143. Thin-film solar overview: cost, types, application, efficiency Available from: [Accessed: December 12, 2021]
  144. 144. Copper indium gallium selenide solar cells. From Wikipedia. Available from: [Accessed: December 12, 2021]
  145. 145. Scheer R, Walter T, Lewerenz H, Fearheiley M. CuInS2 based thin film solar cell with 10.2% efficiency. Applied Physics Letters. 1993;63. DOI: 10.1063/1.110786
  146. 146. Ho SM. Studies of power conversion efficiency and optical properties of Ni3Pb2S2 thin films. Makara Journal of Science. 2017;21:119-124
  147. 147. Rafael J, Jeremy P, Yang C, Vera S, Tonio B, Rupak C. Making record-efficiency SnS solar cells by thermal evaporation and atomic layer deposition. Journal of Visualized Experiments. 2015;99. DOI: 10.3791/52705
  148. 148. Vera S, Jeremy R, Lee Y, Sun L, Helen P, Roy G. 3.88% efficient tin sulfide solar cells using congruent thermal evaporation. Advanced Materials. 2014;26:7488-7492
  149. 149. Teena M, Ramesh K, Naresh N, Venkatesh R. Architecture of monophase InSe thin film structures for solar cell applications. Solar Energy Materials & Solar Cells. 2017;166:190-196
  150. 150. Shinde K, Dubal P, Fulari V, Ghodake G. Morphological modulation of Mn:CdSe thin film and its enhanced electrochemical properties. Journal of Electro Analytical Chemistry. 2014;727:179-183
  151. 151. Ju L, Kim Y, Mahesh P, Uma V, Dong L. Fabrication of Cu2SnS3 thin film solar cells using Cu/Sn layered metallic precursors prepared by a sputtering process. Solar Energy. 2017;145:27-32
  152. 152. Ayaka K, Araki H, Akiko T, Katagiri H. Annealing temperature dependence of photovoltaic properties of solar cells containing Cu2SnS3 thin films produced by co-evaporation. Physica Status Solidi (b). 2015;252:1239-1243
  153. 153. Mingrui H, Kim J, Lokhande A. Fabrication of sputtered deposited Cu2SnS3 (CTS) thin film solar cell with power conversion efficiency of 2.39. Journal of Alloys and Compounds. 2017;701:901-908
  154. 154. Chen Q, Dou X, Li Z, Chen J, Zhou F, Zhuang S. Study on the photovoltaic property of Cu4SnS4 synthesized by mechanochemical process. Optik. 2014;125:3217-3220
  155. 155. Kazuo J, Ryoichi K, Tsuyoshi K, Satoru Y, Win SM, Hideaki A, et al. Cu2ZnSnS4 type thin film solar cells using abundant materials. Thin Solid Films. 2007;515:5997-5999
  156. 156. Hironori K, Kotoe S, Tsukasa W, Hiroyuki S, Tomomi K, Shinsuke M. Development of thin film solar cell based on Cu2ZnSnS4 thin films. Solar energy Materials and Solar Cells. 2001;65:141-148
  157. 157. Wang K, Gunawan O, Todorov T, Shin B, Chey SJ, Bojarczuk NA, et al. Thermally evaporated Cu2ZnSnS4 solar cells. Applied Physics Letters. 2010;97. DOI: 10.1063/1.3499284
  158. 158. Schubert B, Marsen B, Cinque S, Unold T, Klenk R, Schorr S, et al. Cu2ZnSnS4 thin film solar cells by fast co-evaporation. Progress in Photovoltaics. 2011;19:93-96
  159. 159. Chet S, Matthew GP, Vahid A, Brian G, Bonil K, Brian AK. Synthesis of Cu2ZnSnS4 nanocrystals for use in low cost photovoltaics. Journal of the American Chemical Society. 2009, 2009;131:12554-12555
  160. 160. Jonathan JS, Dominik MB, Philip JD. A 3.2% efficient kesterite device from electrodeposited stacked elemental layers. Journal of Electroanalytical Chemistry. 2010;646:52-59
  161. 161. Ennaoui A, Steiner ML, Weber A, Abou-Ras D, Kotschau I, Schock HW, et al. Cu2ZnSnS4 thin film solar cells from electroplated precursors: Novel low cost perspective. Thin Solid Films. 2009;517:2511-2514
  162. 162. Sawanta SM, Pravin SS, Chirayath AB, Popatrao NB, Young WO, Pramod SP. Synthesis and characterization of Cu2ZnSnS4 thin films by SILAR method. Journal of Physics and Chemistry of Solids. 2012;73:735-740
  163. 163. Tsukasa W, Tomokazu S, Shin T, Tatsuo F, Tomoyoshi M, Kazuo J, et al. 6% efficiency Cu2ZnSnS4 based thin film solar cells using oxide precursors by open atmosphere type CVD. Journal of Materials Chemistry. 2012;22:4021-4024
  164. 164. Shinde NM, Dubal DP, Dhawale DS, Lokhande CD, Kim JH, Moon JH. Room temperature novel chemical synthesis of Cu2ZnSnS4 (CZTS) absorbing layer for photovoltaic application. Materials Research Bulletin. 2012;47:302-307
  165. 165. Donghyeok S, Kim Y, Hwang D, Kim D, Son C, Park J. Effect of RF power on the properties of sputtered-CuS thin films for photovoltaic applications. Energies. 2020;13. DOI: 10.3390/en13030688
  166. 166. Karl W. Cadmium sulfide enhances solar cell efficiency. Energy Conversion and Management. 2011;52:426-430
  167. 167. Qiu K, Cai L, Qiu D, Wu W, Liang Z. Preparation of ZnS thin films and ZnS/p-Si heterojunction solar cells. Materials Letters. 2017;198:23-26
  168. 168. Omer S, Arzu E, Sabit H. Synthesis of PbS:Mo(3%) thin film and investigation of its properties. Journal of Materials Science: Materials in Electronics. 2019;30:7600-7605
  169. 169. Wen X, Chen C, Wang C, Tang J, Niu G, Jun Z. Vapor transport deposition of antimony selenide thin film solar cells with 7.6% efficiency. Nature Communications. 2018;9. DOI: 10.1038/s41467-018-04634-6
  170. 170. Liang W, Li D, Chao C, Niu G, Tang J, Fan J, et al. Stable 6% efficient Sb2Se3 solar cells with a ZnO buffer layer. Nature Energy. 2017;2. DOI: 10.1038/nenergy.2017.46
  171. 171. Chao C, Li W, Ying Z, Chen C, Liu X, Bo Y, et al. Optical properties of amorphous and polycrystalline Sb2Se3 thin films prepared by thermal evaporation. Applied Physics Letters. 2015;107. DOI: 10.1063/1.4927741
  172. 172. Manorama L, Mahapatra K, Nandu B. Development of CuInTe2 thin film solar cells by electrochemical route with low temperature (80 °C) heat treatment procedure. Materials Science and Engineering: B. 2016;204:20-26
  173. 173. Lakhe M, Nandu B. Characterization of electrochemically deposited CuInTe2 thin films for solar cell applications. Solar Energy Materials and Solar Cells. 2014;123:122-129
  174. 174. Jia G, Liu J, Zhang W, Li R, Kun W, Yang P, et al. CuInTe2 nanocrystals: Shape and size control, formation mechanism and application, and use as photovoltaics. Nanomaterials. 2019;9. DOI: 10.3390/nano9030409
  175. 175. Hyun Y, Ji H, Joshi B, Ra M, Sam S, Yoon K, et al. CuInSe2 (CIS) thin film solar cells by electrostatic spray deposition. Journal of The Electrochemical Society. 2012;159. DOI: 10.1149/2.jes113086
  176. 176. Se J, Kim C, Yun H, Gwak J, Jeong S, Ryu B, et al. CuInSe2 (CIS) thin film solar cells by direct coating and selenization of solution precursors. The Journal of Physical Chemistry C. 2010;114:8108-8113
  177. 177. Prabukanthan P, Lakshmi R, Tetiana T. Photovoltaic device performance of pure, manganese (Mn2+) doped and irradiated CuInSe2 thin films. New Journal of Chemistry. 2018;42:11642-11652

Written By

Ho Soonmin, Immanuel Paulraj, Mohanraj Kumar, Rakesh K. Sonker and Pronoy Nandi

Submitted: 17 December 2021 Reviewed: 03 January 2022 Published: 07 March 2022