RAMAN AND OPTOELECTRONIC PROPERTIES OF Zn1-xMgxO THIN FILMS PREPARED BY RF MAGNETRON SPUTTERING

Abstract

A series of Zn 1-x Mg x O (x = 0 ~ 0.16) films have been prepared on glass substrates by RF magnetron sputtering. The structure, surface morphology, composition, optical and electrical properties of the films were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), Raman spectroscopy, UV-Vis spectrophotometer and Hall measurement, respectively. It reveals that the obtained films are uniform hexagonal wurtzite polycrystalline with grain size about 100 nm.The optical transmittance are over 80% and the band gap (Eg) has linear relationship with Mg content: Eg = 1.67x + 3.274 (eV) (0 < x < 0.16). The resistivity of the films increases with the increase of Mg content. The Raman spectra of the films show that the position of E2 peaks (473 cm-1) has not changed, but the A1(LO) mode (577 cm-1) frequency shifts to lower wavenumbers with the increase of Mg content, indicating that Mg -doping does not cause intensive lattice deformation, but results in the decrease of the carrier concentration, which is corresponding to the degradation of the conductivity of ZnMgO films with the increase of Mg content.