Materials Research Bulletin, Vol.60, 46-50, 2014
Effects of thermal treatment on the MgxZn1-xO films and fabrication of visible-blind and solar-blind ultraviolet photodetectors
A series of single-phase MgxZn1-xO films with different Mg contents were prepared on quartz substrates by RF magnetron sputtering technique using different MgZnO targets, and annealed under the atmospheric environment. The absorption edges of MgxZn1-xO films can cover the whole near ultraviolet and even the whole solar-blind spectra range, and the solar-blind wurtzite/cubic MgxZn1-xO films have been realized successfully by the same method. In addition, the absorption edges of annealed films shift to a long wavelength, which is caused by the diffusion of Zn atoms gathering at the surface during the thermal treatment process. Finally, the truly solar-blind metal-semiconductor-metal structured photodetectors based on wurtzite Mg0.445Zn0.555O and cubic Mg0.728Zn0.272O films were fabricated. The corresponding peak responsivities are 17 mA/W at 275 nm and 0.53 mA/W at 250 nm under a 120V bias, respectively. (C) 2014 Elsevier Ltd. All rights reserved.