Analytical model for studying the role of ZnS-doped CdS on the performance of CZTSSe solar cells

Copper indium gallium disulfoselenide (CIGSSe)[1, 2] and cadmium telluride (CdTe)[3, 4] have been extensively studied as a promising high efficient absorber material for second generation solar cells. However, the drawbacks of using elements like Cd, Se, In, and Ga as functional layer materials in solar devices, such as their toxicity, abundance, and high cost, have led to the search for alternative materials. These materials could be used in their alternative.[5-7]. Nowadays, Cu2ZnSn (S, Se) 4 (CZTSSe) materials have been considered alternative to expensive and toxic CIGSSe and CdTe thin-film solar cells. These materials have unique properties such as, low cost, earth abundant, p-type electrical conductivity, suitable absorption coefficient (> 104 cm-1) and optimum optical energy gap between 1 and 1.5 eV [8, 9]. In solar cells, and with particular thin film heterojunction solar cells, which depend on their composition on chalcogen materials like Cd-(S, Se, Te), one finds that a CdS thin layer is utilized both as a window material and as a heterojunction partner such as CdTe [10], CuInS2 [11], CuInGaS2 [12], Cu2ZnSn (S, Se) 4 [13] and PbS [14]. However, due to the …