Raman Spectroscopy and In Situ XRD Probing of the Thermal Decomposition of Sb2Se3 Thin Films

b2Se3 thin films have received increasing interest for theirapplications in optoelectronics. However, technological interventiondemands a material-specific understanding of the reactivity to differentenvironments. Both thermal annealing and laser irradiation carried out in anambient atmosphere are expected to induce changes in the pristinecrystallographic phase of Sb2Se3, causing the creation of additionalsecondary phases. Here, we investigate by means of Raman spectroscopythe effect of thermal annealing and laser irradiation at different fluencies onthe structural and vibrational properties of Sb2Se3 thin films. The vacuum-annealed Sb2Se3 thin films at 290 °C and subjected to laser excitation powerabove 2 mW exhibit a secondary phase, revealing the occurrence ofselenization. Further, in situ X-ray diffraction over a broad range ofannealing temperatures in N2 and ambient atmospheres was employed tostudy the structural properties of the Sb2Se3 thin films. In situ XRD performed in a N2 atmosphere does not show the formation ofthe Sb2O3 cubic phase upon annealing until 500 °C. Conversely, a thermally activated systematic crystallization was observed uponannealing in an ambient atmosphere with the formation of the Sb2O3 phase in the temperature range between 280 and 420 °C, untilthe complete decomposition of the material at 500 °C. Further, the orientation of vertically stacked (hk1) planes remains unchangedunder a N2 atmosphere, while horizontally stacked (hk0) planes dominate the (hk1) planes under ambient atmospheres.