Simulating the effect of adding BSF layers on Cu₂BaSnSSe₃ thin film solar cells

In this paper, the device characteristics of Cu₂BaSnSSe₃ (CBT(S,Se₃)) solar cells have been simulated using SCAPS-1D. The simulated results have been validated by comparison with the experimental data reported in the literature. For improving the cell performance and boosting the efficiency, adding different Back Surface Field (BSF) layers is suggested on the absorber layer. Inserting a BSF layer with optimum parameters causes enhancement of open-circuit voltage (V_OC), in particular, causes better efficiency on the cell's performance. For this purpose, we optimize the MoSe₂ layer, which is formed at the interface between CBT(S,Se₃) absorber layer and Mo back contact. Investigation of MoSe₂ helps us to represent optimum ranges for bandgap (E_g), electron affinity (χ), charge carrier density, thickness, the mobility of electron and hole (μ_e and μ_h) and the effective density of states of conduction band and valence band (N_C and N_V) of a material to choose as a BSF layer which can be inserted in CBT(S,Se₃) solar cells and other types of cells like CZTSSe, perovskite and CIGS. Based on the optimum parameters for an appropriate BSF layer, Cu₂BaSnSSe₃ solar cell has been simulated by inserting SnS as a BSF layer, and the results indicated improvement in the cell's parameters. We recorded PCE = 7.31%, V_OC = 0.867 V, J_SC = 16.986 mA/cm², and FF = 49.63.