Influences of rapid thermal annealing on Cu2ZnSnS4 thin film fabricated by spraying approach

Nowadays, Cu2ZnSnS4 is considered as a promising photoabsorption material for thin film solar cells, because of its excellent optical properties. Moreover, it features low cost and eco-friendly. In this work, the spraying approach combined with rapid thermal annealing (RTA) process was employed for the facile fabrication of CZTS thin film. The dependences of as-prepared sample properties on RTA conditions of annealing temperature and annealing time were investigated in detail via X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), ultraviolet-visible-infrared (UV-vis-IR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). As the results suggested, the sample prepared at 600 degrees C for 45 min featured better properties than others. The obtained sample displayed a good crystallinity with kesterite CZTS phase, an acceptable morphology, and a bandgap energy of 1.35 eV. Moreover, this sample presented a desirable Cu-poor and Zn-rich chemical composition with Cu/(Zn + Sn) = 0.86, Zn/Sn = 1.15, and S/(Cu + Zn + Sn) = 0.97, which is favorable for the high-performance photovoltaic devices.

Automated summary

In this study, CZTS thin films were successfully fabricated using a spraying approach combined with rapid thermal annealing, with the sample prepared at 600 degrees C for 45 min exhibiting the best properties. The sample showed good crystallinity, acceptable morphology, and favorable chemical composition for high-performance photovoltaic devices.