Experimental and DFT Study of Structural and Optical Properties of Kesterite-Type Cu2ZnSnS4 Compound for Solar Cell Applications

In this work, Cu2ZnSnS4 (CZTS) thin films were prepared by thermal evaporation from Cu2SnS3 and ZnS initially mixed by a mechanical alloying process. Structural and optical properties of CZTS films have been studied. X-ray diffraction results showed that the semiconductor has the Kesterite structure, and the optical absorption coefficient and band gap energy of the thin films were about 104 cm−1 and 1.46 eV, respectively. The structural and optical properties of Kesterite CZTS, studied by using the full potential linearized augmented plane wave method within the density functional theory, showed good agreement with our experimental results. The surface morphological studies revealed the formation of a smooth, compact and uniform CZTS surface.