Effects of sulfur sources on properties of Cu2ZnSnS4 nanoparticles

In this paper, different shapes of Cu2ZnSnS4 (CZTS) nanoparticles were prepared using different sulfur sources in a microwave irradiation-assisted synthesis method. Factors influencing the morphology and size of the CZTS nanoparticles by different sulfur sources were studied by scanning electron microscopy and transmission electron microscopy. The optical properties of the CZTS nanoparticles were characterized by means of UV–vis–NIR spectroscopy. The results showed that flower-like nanocrystals and hollow sphere-like particles were obtained when using thiourea, thioacetamide, and l-cysteine as sulfur source. The size of CZTS nanoparticles from several nanometers to a few hundred nanometers could be obtained. The band gaps of CZTS nanoparticles became widened with the decrease of the size. A vesicle-template mechanism was proposed to explain the formation process of the hollow structure of CZTS nanoparticles.