Correlation between the optical and electrical parameters of ZnSe thin films

Zinc Selenide (ZnSe) thin films are deposited onto the well cleaned glass substrates using vacuum evaporation method under a vacuum of 3 × 10 ^-5 Torr. Rutherford Backscattering Spectrometry (RBS) is employed to study the composition of the deposited film and the composition of the deposited film is found to be nearly stoichiometric. The deposited film is having cubic structure and is oriented along (111) direction. The particle size, strain and dislocation density are found to be 14.24 nm, 2.74 × 10^-3 lines/m² and 4.9 × 10^-3 lines^-2/m ^-4 respectively. The optical band gap value is evaluated as 2.69 eV. The reflectance spectrum is obtained from the transmittance and absorbance spectra of the films. The refractive index value is calculated from the obtained reflectance spectra and is found to be in the range of 1.57 to 2.48. Drude's theory of dielectric is used to calculate the values of carrier concentration, resistivity and mobility from the optical . studies and the values are found to be 33.8 × 10²⁵ m^-3, 0.62 × 10^-5 Ωm and 33 × 10^-3 m^-3 respectively.