Efficiency Enhancement In Thin Film ITO-cSi Heterojunction Solar Cell Using Photonic Crystal

Abstract

In today's date, it is very important for the solar cell to be both inexpensive and efficient so that we can effectively harness solar power at a lower cost. In this work, we have designed and demonstrated the enhancement in power conversion efficiency of a thin film ITO-cSi hetero-junction photovoltaic cell using photonic crystal as a back reflector making it both cheaper and efficient. The cell structure is analyzed using numerical simulation based on SYNOPSYS RSOFT CAD tool. The structure comprises of an anti-reflection coating of indium tin oxide, a p-type silicon layer and a back surface field layer of p++ type silicon. A photonic crystal (germanium rods in silicon-di-oxide) is implemented at the bottom of the solar cell in order to make the optical path length of incident light longer and reflect back the desired portion of the incident spectrum back to the active region to enhance the absorption process. The projected conversion efficiency as computed by rigorous coupled wave algorithm through RSOFT CAD tool is 27.09% and fill factor of 88.2% at AM 1.5, which is very impressing. A comparison study has also been made to show the enhancement in power conversion efficiency with and without the photonic crystal as a back reflector.