Realization and Characterization of Indium Tin Oxide/Silicon Solar Cells by Spray Pyrolysis Technique

Abstract

The prime objectives of photovoltaic technology are to make solar cells with reasonable efficiency and least cost. Semiconducting materials in the form of thin film with inexpensive processing methods are promising in this context. Thereby, a lab-made spray pyrolysis system is used to prepare indium tin oxide . (ITO) thin films, since this technique is low cost compared with other techniques. The semiconductor I insulator I semiconductor (SIS) structure is a good candidate for photovoltaic solar cell. Mostly ITO thin film is deposited on substrates, which have a suitable work function with respect to ITO. Therefore an inversion layer is induced to form a built-in barrier. The used spray solution to deposit ITO thin layer has a molarity of 0.2 Mole of chemical pure hydrated indium chloride, lnCh:xH20,(99.999%) and different weight ratios of tin chloride, SnC4;5H20, (99%), each one is dissolved in chemical pure ethyl alcohol. Both, the prepared spray solution and the nitrogen carrier gas are fed to the nozzle with pre-determined flow rates. The solution is split to tiny droplets (mist) impinging the substrate surface maintained at a certain temperature. The ITO layer is grown due to the pyrolysis process of the droplet constituents. The preparation parameters that highly affect the film properties such as the substrate temperature, spray time and dopant tin concentration are thoroughly studied.