Growth and properties analysis of metal-organic chemical vapor deposited MgZnO films on -AlO substrates

Abstract

Mg_xZn_1-xO (0 < x ? 0.12) thin films with the wurtzite structure have been successfully grown on c-Al₂O₃ substrates by metal-organic chemical vapor deposition (MOCVD). X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), photoluminescence (PL) spectrometry, and transmission measurements are performed to study the characteristics of Mg_xZn_1-xO thin films. Results show that with increasing Mg content, the diffraction peak of Mg_xZn_1-xO thin films shifts towards a higher diffraction angle (the biggest shift is 0.22°), and the full width at half maximum (FWHM) of the diffraction peak is broadened. Meanwhile, a blue-shift occurs at the near-band-edge (NBE) emission peak and the largest blue-shift of the band gap of the Mg_xZn_1-xO films is 113 meV with Mg content x = 0.12. Therefore, the energy band gap of the Mg_xZn_1-xO films is determined by Mg content in the thin films and the energy band gap increases with an increase of Mg content.

Keywords

Mg_xZn_1-xO / metal-organic chemical vapor deposition / X-ray diffraction / blue-shift