Highly efficient ultra thin Cu(In, Ga)Se2 solar cell with Tin Selenide BSF

Abstract

Cu(In, Ga)Se 2 (CIGS) is a chalcopyrite based semiconductor used as a very promising material for high performance thin film solar cell applications. In this research work, numerical analysis of ultra thin CIGS solar cell towards the possibility of ultra thin layer of CIGS absorber has been performed by using wxAMPS simulator to examine the performance of the proposed cell. The main focus of this work is to explore the performance of ultra thin CIGS solar cell. A conversion efficiency of 19.48% (FF=0.77, Voc=0.86V and Jsc=29.45mA/cm2) has been found for 700 nm CIGS absorber layer without any BSF. It has been found that increased back surface recombination with ultra thin absorber layer deteriorates the cell efficiency. This problem has been solved by inserting a thin layer of Tin Selenide (SnSe) as Back Surface Field (BSF). A better conversion efficiency of 24% (FF=0.80, V oc =0.89V and J sc =33.47mA/cm2) has been achieved for the proposed cell with 700 nm CIGS absorber and 100 nm SnSe layer as BSF. Higher thermal stability has been achieved for the proposed cell with SnSe BSF than without BSF.