Band Gap Engineering Based on Sol-Gel-Derived MgxZn1-xO Thin Films Grown on Muscovite Mica Substrates

Abstract

We studied the dependence of the optical band gap energy and structural properties of the MgxZn1-xO (MZO) thin films on Mg concentration to explore applications in flexible optoelectronics. The MZO thin films were grown on muscovite mica substrates via sol-gel spin-coating. Their surface morphology was smoother and denser than that of ZnO thin film. The peaks were observed for the ZnO thin films at 31.7° and 34.4°, corresponding to the ZnO (100) and (002) planes, but the (100) peak did not appear when Mg was added. The (002) peak of the films was found to be increased with increasing Mg concentration. In the photoluminescence spectra, there were strong UV emissions in the range 3.25.3.45 eV and broad visible emissions were observed for the MZO thin films. The optical band gap calculated from the Tauc``s plot was blue-shifted with increasing Mg concentration. (Received August 13, 2015)