Effect of phosphoric acid treatment on the physical properties of zinc telluride thin films

Zinc Telluride (ZnTe) films were prepared by the closed space sublimation (CSS) method. The effect of chemical treatments with concentrated phosphoric acid, on the optical, electric and structural properties of the films was studied. Zinc-blend structure of the polycrystalline nature of the films was confirmed by x-ray diffraction (XRD) spectra. The energy dispersive x-ray (EDX) shows an increase in Te ratio on the surface of the film as exposed to phosphoric acid. In addition, the dc electrical resistivity of the films was dropped considerably. The refractive index, thickness, and thickness irregularity of the films were determined by fitting of the optical transmittance spectra in the wavelength range 400 to 2500 nm. The effect, of treatment, on the optical parameters is also reported.