Thermally and Optical-Induced Effect on Optical and Electrical Parameters of Ag-Doped CdSe Thin Films

Abstract

Thin films of Ag-doped CdSe are deposited on the glass substrates by thermal evaporation technique using inert gas condensation method. The elemental composition of the prepared thin film is confirmed by EDX spectra. SEM analysis reveals the uniform distribution of the grains over the substrate. TEM analysis reveals the spherical nature of nanoparticles having size in the range of 25–30 nm. X-ray diffraction study indicates an increase in the grain size after thermal annealing and the decrease in the grain size after light soaking treatment. Transmittance spectra are found to decrease with corresponding red shift after annealing and light soaking of as-deposited thin films. The value of the band gap is found to decreases and refractive index increases, after annealing and light soaking treatment. The dispersion of refractive index is described using the Wemple–DiDomenico single oscillator model and the effects of the annealing and the light soaking on the dispersion parameters are studied. The dark conductivity is found to change from 2.24 × 10−8 to 1.54 × 10−7 and 1.45 × 10−9 Ω−1 cm−1 after annealing and light soaking of thin films, respectively. Hall effect measurement reveals n-type behavior of as-deposited, annealed and light-soaked thin films.