Ultra-high sulfurization temperature drives the growth of oxide-derived Cu2ZnSnS4 thin film with very large grain

Abstract

Small grain size is one of the main obstacles for preparing high efficiency Cu2ZnSnS4 (CZTS) photovoltaic devices. The high thermal energy (high annealing temperature) is used to facilitate the driving force of grain growth. In this paper, the CZTS thin films were synthesized by means of sulfurizing oxide-precursors at relatively high sulfurization temperatures (550–700 °C). The effect of sulfurization temperature on properties of CZTS thin films was investigated through XRD, Raman, SEM, and energy dispersive x-ray spectroscopy. Both the crystallinity of the CZTS films and the size of their grains were greatly enhanced, which is attributed to the acceleration of atomic inter-diffusion during the growing process of thin films under ultra-high temperature.

Influence of sulfurization temperature on Cu2ZnSnS4 absorber layer on flexible titanium substrates for thin film solar cells

“…However, it is observed that the grain sizes reduce at about 580 °C. It can be thought that this could be the result of decomposition of CZTS [31,32]. The film morphology and crystallinity become more uniform and denser between 550-570 °C.…”