Effect of Al_2O_3-doping on the structure and optoelectronic characteristics of MgZnO thin film prepared by RF magnetron sputtering

摘要

A systematic study of the effect of Al_2O_3 doping concentration in targets on the structure and optoelectronic characteristics of sputtered MgZnO films was conducted. The films were prepared on glass substrates by radio frequency magnetron sputtering from a MgZnO target mixed with 0-4 wt.% Al_2O_3. X-ray diffraction analysis demonstrated that the Al-doped MgZnO films had a highly (002) preferred orientation with only one intense diffraction peak. The electrical properties of the Al-doped MgZnO films were dependent on the Al_2O_3 concentration. Optimal results of Al-doped MgZnO films were obtained at an Al_2O_3-doping concentration of 2 wt.%, with low resistivity of 2.82 × 10~(-3) Ω-cm and high transmittance of 91% in the visible region. Outstanding electrical properties were achieved because of the significantly increased carrier concentration. The optical bandgap of the Al-doped MgZnO films showed a short-wavelength shift with increased Al_2O_3-doping concentration. The low electrical resistivity and high transparency of Al-doped MgZnO films indicated their potential as transparent conductive oxide window materials for UV optoelectronic devices.