Visible-blind and solar-blind ultraviolet photodiodes based on (In_xGa_(1-x)_2O_3

摘要

UV and deep-UV selective photodiodes from visible-blind to solar-blind were realized based on a Si-doped (In_xGa_(1-x))_2O_3 thin film with a monotonic lateral variation of 0.0035 ＜x＜ 0.83. Such layer was deposited by employing a continuous composition spread approach relying on the ablation of a single segmented target in pulsed-laser deposition. The photo response signal is provided from a metal-semiconductor-metal structure upon backside illumination. The absorption onset was tuned from 4.83 to 3.22 eV for increasing x. Higher responsivities were observed for photodiodes fabricated from indium-rich part of the sample, for which an internal gain mechanism could be identified.