Physical properties of ZnSe 1-x Te x, thin films prepared with a single three-chamber evaporation coaxial source

Abstract ZnSe 1-x Te x thin films were prepared using a single evaporation source specially designed to produce ternary material from the simultaneous sublimation of ZnSe and ZnTe precursor materials. A detailed description of the evaporation source and the procedure for depositing the thin films are given. The substrate temperature allows adequately controlling the Te concentration in the samples. The samples were studied using X-ray Diffraction, Energy Dispersive X-ray, transmittance, room temperature photoluminescence, and photoconductivity in the visible spectral region. The percentage of Te as a function of the substrate temperature was determined using Vegard's Law. Samples grew with the stable cubic structure and were oriented along plane [111]. The crystallite size and thickness of the samples were dependent on the substrate temperature. Absorption values on the order of 10 8  cm −1 and a gap change from 3,0 (x = 0,98) to 3,3 (x = 0,13) eV as the substrate temperature increased from 333 to 623 K were found. The photoluminescence and photoconductivity spectra have contributions of charge recombination through the band gap edge, with localized states below the band gap associated with Zn and Te vacancies in the material. The photoconductivity and photoluminescence signals changed according to the composition of the films.