Investigation of the sulfurization process of Cu2SnS3 thin films with stacked layers CBD-Cu/SnS by rapid thermal process

Abstract

Cu2SnS3 is one kind of new promising material for low-cost thin film solar cells. In this letter, Cu2SnS3 film has been fabricated through sulfurization of Cu/SnS precursors stacked layers by Chemical bath deposition(CBD) with rapid thermal system. To study the growth mechanism of CTS, the phase structural and micro-structural properties of the films with different annealing temperature were taken out carefully. In brief, binary sulfide Cu2−xS forms at low temperature and decomposes to Cu8S5 with the increase of annealing temperature showed by XRD analysis. Gradually, top binary sulfide layer disappears with the generation of Cu2SnS3, which is consistent with the result of SEM that the boundary line disappears with the temperature rising. Moreover, Raman analysis confirms that tetragonal Cu2SnS3 begins transforming to monoclinic Cu2SnS3 at 430°C and monoclinic Cu2SnS3 is obtained at 500°C.