Hydrothermal Synthesis and Evaluation of the Cu₂ZnSnS₄ for Photovoltaic Applications

The research focused on the hydrothermal synthesis of a material based on a Kesterite structure of Cu₂ZnSnS₄ (CZTS). For this purpose, the component cations, in concentrations of 1.0 molL^-1, were placed in a steel autoclave under different temperatures conditions (200, 220, 240, 260 and 280°C) for 32 h. After, the solids were calcined at 400°C for 2 h. UV-VIS results showed that materials had a strong tendency to absorb in the region of 600-800 nm, with band-gap around 1.54 eV. XRD and Raman confirmed a structure with tetragonal geometry, preferably oriented along the (112) facet, as well as low frequency vibrational and rotational modes typical of CZTS. TEM showed nanometric crystallites (≈41.6 𝑛𝑚). XPS showed the Cu²⁺, Sn⁴⁺, Zn²⁺ and S^4- species in correspondence with its main oxidation states. The electrical analysis, allowed to evaluate the behavior under load conditions, suggesting a potential use these materials for photovoltaic applications.

Keywords:
CZTS; Kesterite; Semiconductor