XPS characterization and opto structural study of chemically deposited Sb (III) doped Bi2(Te1-xSex)3 thin films

摘要

Nanocrystalline Sb (III) doped bismuth tellurium selenide [Composition : Bi2-x Sbx(Te1-xSex)3] thin films were successfully deposited in aqueous medium by newly developed Arrested Precipitation Technique (APT) at low temperature. These thin films were prepared using a complexing agent triethanolamine (TEA) and a reducing agent sodium sulphite to avoid hydroxide formation of bismuth precursor Bi (NO3)3 and antimony precursor (SbCl3) in aqueous medium to favor the reaction with Te2- and Se2-chalcogen ions. The preparative conditions such as PH, concentration of precursors, temperature, rate of agitation and time were finalized at initial stages of deposition. As deposited films were annealed at constant temperature (373K) in muffle furnace and then characterized for optostructural, morphological and compositional properties. The results demonstrate that the Bi2-x Sbx(Te1-xSex)3 thin films prepared by APT shows band gap in the range 1.46eV to 1.89eV. X-Ray Diffraction (XRD) pattern, Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) images reveals that Bi2-x Sbx(Te1-xSex)3 mixed metal chalcogenide films are of nanocrystalline nature and have rhombohedral structure and better morphology. EDAX and XPS study shows good stoichiometry. Hence APT is simple and suitable for deposition of Sb (III) doped bismuth tellurium selenide thin films