Solar Cells produced using semiconductor-insulator-semiconductor (SIS) Structures Obtained by Spray Pyrolysis

Dr. Leonid Izmail Bruk works as a senior researcher at the Semiconductor Physics Laboratory at the State University of Moldova. Solar cells fabricated on the basis of semiconductor-insulator-semiconductor (SIS) structures are promising systems for solar energy conversion due to their relatively low cost. These structures are obtained by deposition of transparent conductive oxide (TCO) films onto different crystal substrates: Si, CdTe, InP and others. The simplest method of obtaining TCO films is the deposition of SnO₂, In₂О₃ or their mixture Indium Tin Oxide (ITO) by spray pyrolysis. The resulting thin films are used for formation of SIS structures with a shallow junction. At the same time the ITO thin film can play the role of a frontal collecting electrode and an antireflection layer. Solar cells obtained by this method have efficiency ratings of approximately 10%. They may be grouped in modules with different electrical power to be used as power supplies for electric devices. It is possible to use silicon plate rejects from the electronics industry for manufacturing such solar cells. This method of obtaining ITO layers does not require expensive equipment and highly skilled personnel. The temperature of silicon-ITO solar devices is 400-450°C, that is, much lower than the temperature for obtaining p-n transition in silicon (1400°C).This simple method can be used in small production facilities.