Marcela Socol

By Marcela Socol, Nicoleta Preda, Anca Stanculescu, Florin Stanculescu and Gabriel Socol

Multilayer or blend heterostructures based on porphyrins and phthalocyanines were obtained on different substrates using VTE and MAPLE methods. Stacked structures based on ZnPc and C60 with NTCDA were prepared by VTE on ITO/glass, their current value being increased by the deposition of the materials in an inverted configuration or by using ITO/PEDOT:PSS as a substrate. Multilayer structures comprising ZnPc and NTCDA were fabricated by MAPLE on an AZO/glass. Treating the AZO in oxygen plasma, a higher current value was obtained for the deposited heterostructures. The oxygen plasma treatment can increase the work function of the AZO resulting in a decrease of the energetic barrier from AZO/organic interface and finally improving the charge transport. Stacked layers or blend heterostructures having ZnPc, MgPc and TPyP were deposited by MAPLE on ITO/PET. In the case of those containing MgPc and TPyP, an increase in the current value (in dark) was obtained for the blend compared to the stacked layer configuration. For those with ZnPc and TPyP, under illumination, a photovoltaic effect was observed for the blend structure. All heterostructures are featured by a large absorption in the visible domain of the solar spectrum and suitable electrical properties for their use in OPV applications.

Part of the book: Phthalocyanines and Some Current Applications

By Marcela Socol, Nicoleta Preda, Carmen Breazu and Oana Rasoga

Transparent conductive oxide (TCO) electrodes are key components in the fabrication of optoelectronic devices such as organic photovoltaic cells (OPVs) or organic emitting devices (OLEDs). Pulsed laser deposition (PLD) results in TCO coatings with adequate optical and electrical properties, the preservation of the target chemical composition in the transferred films being the major advantage of this technique. Furthermore, the performance of the optoelectronic devices can be enhanced by patterning the TCO electrodes. Indium tin oxide (ITO) remains the most popular TCO due to its high conductivity and transparency. The scarcity of the indium resources encouraged the efforts to find an alternative to ITO, a promising candidate being Al-doped ZnO (AZO). Therefore, this chapter is focused on PLD deposition of TCO films (ITO and AZO) on patterned glass substrates prepared by ultraviolet nanoimprint lithography (UV-NIL) for obtaining transparent electrodes with improved characteristics, which further can be integrated in optoelectronic applications.

Part of the book: Thin Films