Mg_xZn_(1-x)O thin film and UV detector for solar-blind wavelength

MgxZn1-xO is a promising material for developing solar-blind ultraviolet(UV) photodetectors.However,the control of the MgZnO quality and the phase separation with increase of Mg in MgxZn1-xO alloy is still a difficult problem.Up to now,no reports that the cutoff wavelength is at 273 nm have been found for the photodetectors based on MgZnO films.In this paper,cubic MgxZn1-xO thin films are grown on quartz and sapphire substrates by Radio Frequency(RF) magnetron sputtering and Metal Organic Chemical Vapour Deposition(MOCVD).The Metal-Semiconductor-Metal(MSM) structured MgZnO photodetectors are fabricated based on the films.Results from spectral analysis shows that the photodetector exhibits a peak response wavelength at 225 nm with a cutoff wavelength of 230 nm,and the cubic phase MgZnO alloy with 255 nm absorption edge is finished by LP-MOCVD and the MSM devices exhibit the peak energy at 250 nm with cutoff wavelength of 273 nm,which lies in the solar-blind spectrum range(220~280 nm).