Electroluminescence Transition From Visible- to Ultraviolet-Dominant Mode in \n-Mn0.04\Zn0.96\O/i-ZnGa2\O4\/ \n-GaN Structure With Highly Ultraviolet Detection Performance.

We report an \n-Mn0.04\Zn0.96\O\!(\MZO)\! \/\i-ZnGa2\O4\!\/\break\n-GaN structure both as a light-emitting diode and as an ultraviolet (UV) photodetector at forward and reverse biases, respectively. The n-MZO films were prepared on n-GaN coated sapphire substrates, followed by postdeposition thermal annealing treatment at 700 ^\circ\C, and an \i-ZnGa2\O4 interface layer was formed at the MZO/GaN interface after the annealing treatment. We found that the electroluminescence characteristics showed a transition from visible- to UV-dominant mode when the deposition temperature of the MZO film is from 100 ^ \circ\C to 300 ^\circ\C. For the UV detection performance, the devices based on the low-temperature deposition (100 ^\circ\C) of the MZO film showed the lowest dark current and the biggest ratio of photocurrent to dark current with a selectivity detectivity for 365 nm around light. [ABSTRACT FROM PUBLISHER]