Mg0.55Zn0.45O solar-blind ultraviolet detector with high photoresponse performance and large internal gain

A Schottky type metal-semiconductor-metal solar-blind ultraviolet detector was fabricated on high quality wurtzite Mg0.55Zn0.45O epitaxial film. Photoresponse spectra show a responsivity peak of 22 mA/W under 130 V bias. A sharp cutoff was recognized at a wavelength of 270 nm, and a temporal response measurement indicates a fast decay time of less than 500 ns. A large internal gain was observed and interpreted by a reduced Schottky barrier height model, which fits well with the experimental data.