Annealing effects on optical and structural properties of chromium oxide thin film deposited by PLD technique
Optical properties of chromium oxide (Cr2O3) thin films which were prepared by pulse laser deposition method, onto glass substrates. Different laser energy (500-900) mJ were used to obtain Cr2O3 thin films with thickness ranging from 177.3 to 372.4 nm were measured using Tolansky method. Then films were annealed at temperature equal to 300 °C. Absorption spectra were used to determine the absorption coefficient of the films, and the effects of the annealing temperature on the absorption coefficient were investigated. The absorption edge shifted to red range of wavelength, and the optical constants of Cr2O3 films increases as the annealing temperature increased to 300 °C. X-ray diffraction (XRD) study reveals that Cr2O3 thin films are amorphous; while the crystal structure of annealed Cr2O3 films is rhombohedral after annealing at 300 °C for two hour. AFM studies of Cr2O3 thin films exhibit a smooth and well dispersed on the surface.