Investigations on structural, optical and electrical parameters of spray deposited ZnSe thin films with different substrate temperature

Abstract

ZnSe thin films have been deposited on high cleaned glass substrate by spray pyrolysis technique within the glass substrate temperature range (400 ○C to 450 ○C). The structural properties of ZnSe thin films have been investigated by (XRD) X-ray diffraction techniques. The X-ray diffraction spectra showed that ZnSe thin films are polycrystalline and have a cubic (zinc blende) structure. The most preferential orientation is along the (111) direction for all spray deposited ZnSe films together with orientations in the (220) and (311) planes also being abundant. The film thickness was determined by an interferometric method. The lattice parameter, grain size, microstrain and dislocation densities were calculated and correlated with the substrate temperature (TS). The optical properties of ZnSe thin films have been investigated by UV/VIS spectrometer and the direct band gap values were found to be in the region of 2.65 eV to 2.70 eV. The electrical properties of ZnSe thin films have been investigated using the Van der Pauw method and the high quality ZnSe thin films were observed to develop at 430 ○C with a resistivity of 56,4×105 ohm cm, a conductivity of 1.77×10-7 (Ω cm)-1 and a hall mobility of 0.53 cm2/Vsec.