Effect of Annealing Process on Optical, Electrical and Surface Properties of ZnO films

Zno films were prepared on glass at 300±5 °c substrate temperature by ultrasonic spray pyrolysis. the deposited films were annealed at various temperatures (350, 450, 550 °c) for 2 hours. annealed and unannealed of zno films were characterized by studying their optical, electrical and surface properties. the optical transmittance and absorbance spectra of all films were examined by uv-vis spectrophotometer and the optical band gap was found using optic method. besides, visible emission peaks and native point defects of zno films were determinate using photoluminescence spectra. thickness, refractive index and extinction coefficient values were obtained with spectroscopic ellipsometry technique. the electrical and surface properties of the films were characterized four point technique and atomic force microscopy, respectively. according to result, the effects of annealing temperature on the optical, electrical and surface properties of the zno films are discussed.