AlxGa1-xN-based avalanche photodiodes with high reproducible avalanche gain

The authors report high performance solar-blind photodetectors with reproducible avalanche gain as high as 1560 under ultraviolet illumination. The solar-blind photodetectors have a sharp cutoff around 276 nm. The dark currents of the 40 mu m diameter devices are measured to be lower than 8 fA for bias voltages up to 20 V. The responsivity of the photodetectors is 0.13 A/W at 272 nm under 20 V reverse bias. The thermally limited detectivity is calculated as D-*=1.4x10(14) cm Hz(1/2) W-1 for a 40 mu m diameter device. (c) 2007 American Institute of Physics.