Impact of Sb Incorporation on the Structural and Optical Properties of CZTS Thin Films Grown by Spin Coating Technique

Undoped and Sb-doped, Cu2ZnSnS4 (CZTS) thin films have been synthesized on ordinary glass slides using the sol-gel spin coating method. The effect of variation in Sb doping concentration on structural, optical, and surface morphological characteristics of CZTS thin films has been investigated. The XRD analysis reported that these samples show a kesterite phase which is further confirmed by Raman spectra. The crystallite size for CZTS thin film samples increases from about 9 nm to 15 nm. The surface morphology of CZTS thin films has been investigated by SEM analysis. The chemical composition of existing elements has been presented by EDS analysis. The optical properties have been examined by UV-Vis spectrometer. For synthesized thin films energy band gap values vary from 1.90 eV to 1.62 eV and the refractive index varies from 2.74 to 2.85. Additionally, the high-frequency dielectric constant (ε∞) and static dielectric constant (ε0) values have been determined.