Numerically investigating the AZO/Cu2O heterojunction solar cell using ZnO/CdS buffer layer

Aluminium (Al)-doped zinc oxide (ZnO)/copper oxide (AZO/Cu2O) heterojunction solar cell is analyzed by a 1-D solar cell capacitance simulator (SCAPS-1D). The influence of single (CdS) and double (ZnO and CdS) buffer layers on the performance of AZO/Cu2O heterojunction solar cells is studied. The effects of device parameters such as Cu2O acceptor and CdS donor doping concentrations, external quantum efficiency, interface states density, metal work function, absorber and buffer layer thicknesses, and working temperature on both single and double buffer layer solar cell are carried out. The optimized solar cell structure of single buffer AZO/CdS/Cu2O/Au and double buffer AZO/ZnO/CdS/Cu2O/Au results in the power conversion efficiency (PCE) of 10.47 and 10.60 %, short circuit current density (J(SC)) of 11.33 and 11.37 mA cm(-2), open-circuit voltage (V-oc) of 1.1381 and 1.1405 V and fill factor (FF) of 81.21 and 81.74 %, respectively under illumination. Our findings reveal that the PCE of AZO/Cu2O based heterojunction thin-film solar cell is enhanced through the usage of a double buffer (ZnO/CdS) layer in comparison to the single (CdS) buffer layer.