Performance Analysis for SnS- and Sn2S3-Based Back Surface Field CZTSSe Solar Cell: A Simulation Study.

CZTSSe-based solar cell structures have shown remarkable properties in terms of their low cost, greater stability, high absorption coefficient, and relatively inexpensive production process. However, their maximum achieved values of power conversion efficiency remain low, close to 12.6%. This is mainly due to the problem of back surface carrier recombination. In this paper, we present the results of studies carried out using the SCAPS-1D tool to test the viability of deploying SnS (tin sulphide) and Sn₂S₃ (tin(IV) sulphide) materials as a back surface field (BSF) layer, due to their inherent advantage of having a similar material composition as CZTSSe. A detailed analysis is carried out on CZTSSe and BSF layer doping variation and CZTSSe/BSF interface defect density to optimize the photovoltaic (PV) performance of the devices. The results reflect an increase in the efficiency from 12.57% to 16.34% (with SnS BSF) and 17.04% (with Sn₂S₃ BSF). The cell with the SnS BSF delivers an open-circuit voltage (V_OC) of 0.59V, a short-circuit current density (J_SC) of 37.74 mA/cm², and a fill factor (FF) of 73.36%, while the device with the Sn₂S₃ BSF delivers V_OC of 0.59V, J_SC of 37.68 mA/cm² and FF of 76.46%. The results reported in this study could open a pathway to realize high-efficiency CZTSSe solar cell structures in the future. [ABSTRACT FROM AUTHOR]