Characteristics of SnSe and SnSe2 thin films grown onto polycrystalline SnO2‐coated glass substrates

Tin selenide thin films have been prepared by selenization of sputtered tin layers and have been analyzed comparatively onto bare and SnO2‐coated glass substrates. In particular, the effects of the selenization temperature and the polycrystalline substrate nature on the stoichiometry and physical properties of the layers were investigated. X‐ray diffraction was used to determine the crystalline phases and their structure, scanning electron microscopy to observe the surface topography, energy‐dispersive X‐ray analysis to establish the film composition, and spectrophotometry to determine the optical absorption, all these properties correlated to the experimental parameters. By using polycrystalline tin oxide coatings it is possible to achieve a significant crystalline enhancement for the SnSe and SnSe2 phases identified, being the Se:Sn atomic proportion, as well as the optical absorption, highly dependent on the selenization temperature apart from the substrate nature.