Relative Simulation Analysis of Cadmium Sulfide (CdS) and Tin Sulfide (SnS₂) As a Buffer Layer in CuInSe₂-Based Thin Film Solar Cell

Chalcopyrite I–III–VI2-based solar cells include CuInSe2 material, which is one of the inordinate chalcopyrites. Observation of the relationship between the input variable parameters and output parameters for the CISe2-based solar cell is studied by SCAPS-1D software. This study covers a Mo/CISe2/CdS/ZnO/Al–Ni solar cell with the Al–Ni composite layer as a front metal contact. Mo/CISe2/SnS2/ZnO/Al–Ni heterojunction solar cell was used in the next simulation. SnS2 material was used instead of the CdS layer because of its properties like environmental friendly element, flexible bandgap, nontoxicity, and large natural abundance. The shallow uniform density parameter is simulated or optimized for the absorber layer (CuInSe2) and the ZnO layer. The shallow uniform donor density and the thickness were optimized for the SnS2 layer. Also, a comparative optical study was performed for both the CdS layer and the SnS2 layer in the CISe2 solar cell. In this paper, the CISe2 solar cell with a CdS layer obtained a fill factor (FF) of 84.85%, an optimal photoelectric conversion efficiency (Eff) of 20.60%, an open circuit voltage (Voc) of 0.78 V, and a short circuit current density (Jsc) of 30.98 mA/cm2, and that with an SnS2 layer obtained a fill factor (FF) of 85.22%, efficiency (Eff) of 20.84%, open circuit voltage (Voc) of 0.78 V, and short circuit current density (Jsc) of 31.19 mA/cm2. The outcomes obtained by these numerical calculations are helpful in the development of high-efficiency solar cells.