Effect of Hydrothermal Temperature on Structural Morphological and Optical Properties of Facile Hydrothermally Synthesised Cu2ZnSnS4 Nanomaterials

Abstract

Cu2ZnSnS4 (CZTS), semiconductor has proven to be a low cost promising absorber material with high optical absorption coefficient and an ideal band gap for photovoltaic applications. This work presents a facile hydrothermal synthesis of a CZTS nanocrystalline material using Polyacrylic acid (PAA) as surfactant. The effect of hydrothermal synthesis temperatures between 150 and 270oC (in steps of 40oC) on the phase, composition, microstructure and morphology were investigated. Pure kesterite CZTS were obtained, composed of spherical shaped flower-like aggregated nanoparticles, with particle sizes ranging between 10 and 19 nm. The Cu/Zn/Sn ratio were near the ideal stoichiometric ratio for samples synthesised at 150 and 170oC, while those synthesized at 230 and 270 hydrothermal temperatures show considerable deviation. The obtained bandgaps were about 1.51 eV.