OPTIMIZATION OF SULPHURIZATION TEMPERATURE FOR OBTAINING DENSE Cu_2ZnSnS_4 FILMS WITH PHASE PURITY AND PREFERRED COMPOSITION

摘要

This study focusses on the effect of sulphurization temperature on properties of Cu_2ZnSnS_4 (CZTS). Cu-Zn-Sn precursor films were co-electrodeposited using electrolyte containing salts of Cu, Zn and Sn and a complexing agent (tri-sodium citrate) followed by sulphurization in inert atmosphere (Ar) at different temperatures ranging from 250°C to 600°C for 30 minutes. Samples sulphurized at these temperatures were characterized for structure, morphology and composition. XRD and Raman spectroscopy suggested that, sample sulphurized at 500°C has a phase purity unlike samples sulphurized at 450°C, 550°C and 600°C which showed peaks corresponding to CZTS phase along with some impurity phases. SEM images for samples sulphurized at 450°C, 500°C, 550°C and 600°C indicated compact morphology but, only the sample sulphurized at 500°C showed preferred composition for CZTS absorber material. Structural, morphological, compositional studies suggested that, sample sulphurized at 500°C resulted in CZTS film with characteristics for an absorber layer for thin film solar cell.