Spray Pyrolysis of Nano-Structured Optical and Electronic Materials

Abstract

This chapter focuses on the fundamentals of the spray pyrolysis (SP) technology, the formation of oxide nano powders, nano rods and nanocrystalline thin films, and the performance/manufacturing condition relationships of these materials. Specific application areas such as photovoltaic, energy storage, and sensors will also be given in a subsection of the chapter. Moreover, our approach to building nanocrystalline chalcopyrite semiconductor thin films for photovoltaic applications is given. Chalcopyrite semiconductors are good alternatives to silicon-based photovoltaic devices because of their appropriate band gap energy, high absorption coefficient, and stability. Although selenium-based chalcopyrite materials have very high energy conversion efficiencies in photovoltaics, sulfur-based semiconductors have been quickly replacing them due to the non-toxicity of the sulfur-containing materials. This chapter gives information on the nanocrystalline thin-film deposition of both selenium- and sulfur-based chalcopyrite semiconductors via SP. Applications of these materials in the photovoltaic area are also discussed. Furthermore, our very recent work on the SP of copper-based photovoltaic devices on flexible substrates is summarized. Usage of flexible substrates, polymers, and metal foils, which combine the advantages of being very lightweight with mechanical robustness, is discussed. Therefore, spray-pyrolyzed materials can be used in flexible electronic applications or in the areas where the weight/volume ratio is crucial like unmanned air vehicles.