Structural and optical properties of Zn1-xMgxO thin films deposited by ultrasonic spray pyrolysis

Abstract The structural and optical properties of Zn 1− x Mg x O films deposited by ultrasonic spray pyrolysis were studied. All the Zn 1− x Mg x O thin films maintained the ZnO wurtzite structure and had no impurity phase, even for the Mg content up to x = 0.27. The optical properties were characterized by transmittance, absorption spectroscopy and photoluminescence measurements. For all the films, the average transmission in the visible wavelength region ( λ = 400–800 nm) was over 85%, and the absorption edge shifted to a shorter wavelength as the Mg content increased. The optical energy band gap of Zn 1− x Mg x O thin films, measured from transmittance spectra, could be controlled between 3.29 and 3.58 eV by adjusting Mg contents. The photoluminescence emission peaks of Zn 0.94 Mg 0.06 O and Zn 0.73 Mg 0.27 O thin films were located at 369 and 349 nm, showing an evident blue-shift with Mg content increase. The room temperature absorption and photoluminescence properties of the films were also discussed.