Synthesis and Characterization of Next Generation Cu2ZnxFe1−xSnS4 (x = 0, 0.25, 0.5, 0.75 and 1) Compounds

Abstract

In this paper, we investigate the effect of Zn/Fe ratio on the properties of Cu2ZnxFe1−xSnS4 (CZFTS) compounds. Multicomponent CZFTS powders were prepared by direct melting of the constituent elements taken in stoichiometric compositions. After that, CZFTS thin films were fabricated using a single source vacuum thermal evaporation method. After that, CZFTS thin films were annealed in sulfur atmosphere under nitrogen flow at 400°C for 30 min. Structural properties of CZFTS powders and thin films were studied by elemental composition measurement, x-ray diffraction (XRD) and Raman spectroscopy. Analysis of chemical compositions reveals that the synthesized CZFTS powders are close to the expected stoichiometry. XRD patterns and Raman spectra of CZFTS powders showed that only polycrystalline CZFTS phase is present and a possible transition phase from stannite to kesterite structure had occurred by reducing Fe content. Using XRD data, the crystal parameters of CZFTS powders were estimated. Structural properties of CZFTS thin films indicate an enhancement of crystallinity after annealing. Some microstructural parameters of the prepared films were evaluated. However, morphological analysis of CZFTS crystals showed compact surfaces. Also, micrographs of CZFTS thin films indicate an improvement of crystallinity films followed by the increases of average roughness values after a sulfurization process. Moreover, hot probe method indicates that CZFTS ingots and prepared films exhibit an obvious p-type semiconductor.