Numerical simulation on an efficient n-CdS/p-ZnSnN2/p+-Cu2SnS3/p++- CuGaSe2 thin film solar cell

Numerical simulations have been carried out to inspect the photovoltaic (PV) performance of ZnSnN2 (ZTN) based PV device with a thin Cu2SnS3 (CTS) current raising layer. In the model, CdS and CuGaSe2 (CGS) are exerted as the window and back surface field (BSF) layers, in turn. The thickness, doping concentration and defect density of each layer have been optimized to determine the PV parameters. The CdS/ZnSnN2 single heterostructure provides the photovoltaic parameters: VOC of 0.96 V, JSC of 27.01 mA/cm2, FF of 82.83% and PCE of 21.59%, respectively. The current of the cell rises to 37.37 mA/cm2 with the efficiency of 32.75% owing to the addition of a thin CTS absorber layer in that structure. Finally, the CGS BSF within the n-CdS/p-ZTN/p+- CTS/p++-CGS heterojunction significantly improves the VOC to 1.169 V which results the efficiency of 37.79% with JSC of 39.41 mA/cm2 and FF of 82.03%. These sequels are optimistic for the build of proficient ZTN solar cells.