GRAIN-BOUNDARY EFFECT IN POLYCRYSTALLINE ZNTE FILMS

Electrical and optical properties of ZnTe films, deposited at differen t substrate temperatures (300-630 K) by hot-wall vacuum evaporation, w ere studied. The experimental data were analysed in the light of the g rain boundary trapping model in polycrystalline films. The crystallite s were found to be partially depleted of carriers. The barrier height along with the carrier concentration in the films were determined from the optical reflectance measurements. The effect of deposition temper ature on the film properties has been critically discussed. The densit y of trap states in the intercrystalline region of the films was found to decrease with increasing deposition temperature. The built-in elec tric field in the crystallites was evaluated for different sizes of th e crystallites.