Modeling and performance study of CZTS solar cell with novel cupric oxide (CuO) as a bilayer absorber

Abstract

A Kesterite material like CZTS provides the steering to the researcher with their tunable bandgap and high optical coefficient above 10⁴ cm⁻¹ for solar cells. These features make it a suitable material for a single junction solar cell increasing the acceptance as well. In this paper, comparative numerical simulations were performed on a regular base structure of CZTS absorber layer with a CdS buffer layer, a ZnO window layer, and a transparent n-ITO conducting layer with a proposed structure where CZTS absorber layer is replaced by a CZTS and CuO bi-layer using SCAPS-1D software to optimize the efficiency. In addition to that the thickness, defect densities and doping concentrations of the absorber layers and temperature were varied to observe the responses of open-circuit voltage (V_OC), short-circuit current (J_SC), fill factor (FF) and efficiency (η) of the solar cell. Among the three basic researchs on lost mechanism for kesterite materials, we have focused on improving the back contact interface recombination through an absorber bi-layer combination of CZTS and CuO resulting in increased V_OC, Quantum efficiency and carrier generation efficiency approximately by 50 %, 8.94 %, and 34 % respectively, elevating the efficiency of the proposed structure to 19.92 %.