SnxSy compounds growth by controlled sulfurisation of SnO2

In this work, thin layers of semiconducting tin sulfide Sn_xS_y compounds have been prepared by sulfrisation of tin oxide SnO₂ on glass substrate. Structural studies showed that, depending on sulfur supply concentration, a mixture of SnS₂ and Sn₂S₃ is obtained at an annealing temperature of 550 °C for 2 h. From the transmission and reflectance spectra, the extinction coefficient and refractive index were calculated as guides to understanding crystal growth kinetics. On the other hand, the exploitation of these optical measurements along with optothermal investigations showed that the electronic transitions in these layers were of allowed direct type and exhibit two gaps indicating the presence of two competent sulfide phases: SnS₂ and Sn₂S₃.