Solar-blind AlGaN-based p-i-n photodetectors with high breakdown voltage and detectivity

We report on the high performance solar-blind AlGaN-based p-i-n photodetectors that are grown by metal-organic chemical vapor deposition on c-plane sapphire substrates. The dark current of the 200μm diameter devices was measured to be on the order of 5fA for bias voltages up to 10V. The breakdown voltages were higher than 200V. The responsivities of the photodetectors were 0.052 and 0.093A∕W at 280nm under 0 and 40V reverse biases, respectively. We achieved a detectivity of 7.5×1014cmHz1∕2∕W for 200μm diameter AlGaN p-i-n detectors.