Theoretical Investigation of the Influence of Defect States on the Power Conversion Efficiency of CZTSSe Solar Cells

This report presents a performance variation analysis in the presence of defect states in CZTSSe (Copper Zinc Tin Sulphur Selenide) solar cell. The presence of defect states inside the bulk of absorber layer and at interface between absorber and buffer layers were simulated and analyzed. It is observed that the extent of recombination losses gets affected by the presence of defects states in the bulk/interface and it is more prominent near the interface region than in the bulk region. The recombination losses led to the reduction in the values of open circuit voltage (V
_∝
), short-circuit current density (J
_sc
) and the overall power conversion efficiency (PCE) of the device in comparison to that generally achieved in CIGS and CdTe solar cells. These results highlight the need for a systematic study dedicated towards the lowering of interfacial/bulk defects to achieve the performance of CZTSSe solar cells comparable to other high performance solar cells.