A series of MgxZn1−xO thin films has been prepared by metalorganic chemical vapor deposition and metal-semiconductor-metal structured ultraviolet photodetectors are fabricated from these films. The cutoff wavelengths of the photodetectors can cover the whole solar-blind spectrum range (220–280 nm) by varying Mg content in the MgxZn1−xO thin films. As a representative, the photodetector fabricated from Mg0.52Zn0.48O shows an ultraviolet/visible rejection ratio of about four orders of magnitude, and the dark current is 15 pA at 10 V bias. These results demonstrate that high-performance photodetectors operating in the whole solar-blind spectrum range can be realized in MgxZn1−xO films.

Surface plasmons, a unique property of metal nanoparticles, have been widely applied to enhance the performance of optical and electrical devices. In this study, a high quality zinc oxide (ZnO) thin film was grown on a quartz substrate by a radio frequency magnetron sputtering technique, and a metal-semiconductor-metal structured ultraviolet detector was prepared on the ZnO film. The responsivity of the photodetector was enhanced from 0.836 to 1.306 A/W by sputtering metal (Pt) nanoparticles on the surface of the device. In addition, the absorption of the ZnO thin film was enhanced partly in the ultraviolet band. It is revealed that Pt nanoparticles play a key role in enhancing the performance of the photodetectors, where surface plasma resonance occurs.

No abstract