Effect of Annealing Temperature on Morphology and Optoelectronics Properties of Spin-Coated CZTS Thin Films

Abstract

The effect of different annealing temperatures (300, 400, 500 and 550 °C) on the crystallinity, morphology, linear and particularly the nonlinear optical properties of CZTS thin films that were deposited on glass substrate employing a sol–gel spin-coating method was investigated in this work. The obtained results for X-ray diffraction (XRD) indicate a polycrystalline structure of CZTS thin film, the scanning electron microscopy (SEM) and atomic force microscopy (AFM) micrographs showed a uniform and dense texture of the samples, besides the effect of annealing temperatures on CTZS morphology and surface was discussed. Linear optical properties of CZTS thin films were performed by UV–Vis spectrophotometer, both band-gap energy and absorption coefficient were determined and extracted from the variation of the optical transmission and absorption with the wavelength, Eg of the films annealed at 300, 500 and 550 °C was found to be 1.58 eV against 1.63 eV for the film annealed at 400 °C. However, the optical nonlinearity characterizations of CZTS films examined by third harmonic generation (THG) technique exhibited an interesting nonlinear optical responses between 1.10 × 10–20 and 1.84 × 10–20 m2 V−2 which can enlarge the application field of the studied material.