Optical properties of multi layers MnO/Sb/MnO thin films prepared by electron-beam evaporation technique

Films of MnO/Sb/MnO were deposited onto microscopic glass substrates by electron beam evaporation technique. The effect of annealing temperature on transmission, reflection and other optical properties were studied. The transmission and reflection spectra were measured in the wavelength range from 200 to 2,500 nm. The film morphology was examined by scanning electron microscope (SEM). The obtained results from SEM showed that the grain size of MnO/Sb/MnO films increased with increasing annealing temperature. The as-deposited films and films annealed at low temperature showed very low transmission in the visible region and high reflection in the ultraviolet region. At annealing temperature of 550 °C, prepared films showed optical transmission about 85 % in the visible region and their reflection exceeded 50 % in ultraviolet region. Furthermore, it was found that other optical parameters such as energy gap, extinction coefficient, refractive index and dielectric constants were strongly dependent on the annealing temperature process. (author)