Nnditshedzeni Eric Maluta

By Akin Olaleru, Eric Maluta, Joseph Kirui and Olasoji Adekoya

Hybrid perovskite thin film offers diverse advantages like low cost deposition techniques, less material consumption and superior optoelectronic properties. These merits including high voltage and high efficiency performance in a wide range of high light intensity are sufficient to distinguish perovskite thin films/devices from their contenders as a thin film technology with greater potential for industrial applications. Perovskite thin film technology demonstrates potency in a variety of applications in optoelectronic devices especially photovoltaic applications. The National Renewable Energy Laboratory (NREL) of the USA categorizes a number of thin films technologies including perovskite thin film, as emerging photovoltaics with the bulk of them yet to be commercially applied but are still in the research or developmental stage. In this chapter, various processing methods and material combinations as well as current trends in this technology are subjects of discussion.

Part of the book: Thin Films Photovoltaics

By Lutendo Phuthu, Nnditshedzeni Eric Maluta and Rapela Regina Maphanga

Due to its properties, graphene is considered a revolutionary material for the future, and as a two-dimensional material it has received a lot of research attention over the last two decades. For graphene to be used in different technologies such as solar cells, much more work needs to be done to understand its properties and engineer its properties by combining it with other materials such as semiconductors. This research work reports computational investigation of the electronic and optical properties of Ti and Ru mono-doped and co-doped graphene. Geometry optimizations for the electronic and optical properties were performed by first-principles calculations based on density functional theory. Various supercells of graphene were modeled and optimized, and their properties were calculated. The results show that different graphene supercells have different electronic and optical properties. The energy bandgap of pure graphene is zero, and after doping with Ti and Ru it increases to 0.550 eV, and 0.786 eV, respectively. The co-doped graphene bandgap is 0.272 eV. The calculated optical properties showed that doping graphene with Ti and Ru shifts the absorption from the visible to the near-infrared region, and these results open possibilities of using doped graphene as a semiconductor material.

Part of the book: Graphene

By Akin Olaleru, Joseph Kirui, Olasoji Adekoya and Eric Maluta

Several data on the preparation of perovskite crystals have been obtained because samples/devices were prepared using films of different qualities. Identifying optimal conditions for perovskite material synthesis and thin film preparation as well as optimizing the properties will go a long way in reducing the disparities in the data obtained. The optimal composition management of various elements of perovskite remains an outstanding research. The chapter will pave the way for the optimum design of the synthesis process of perovskite-based devices for better performance. Further still, the study provides basis for explaining the effective optimizations of synthesis conditions and material properties.

Part of the book: Recent Advances in Multifunctional Perovskite Materials