High-speed characterization of solar-blind AlxGa1-xN p-i-n photodiodes

We report on the temporal pulse response measurements of solar-blind AlxGa1-xN-based heterojunction p-i-n photodiodes. High-speed characterization of the fabricated photodiodes was carried out at 267 nm. The bandwidth performance was enhanced by an order of magnitude with the removal of the absorbing p+ GaN cap layer. 30 mum diameter devices exhibited pulse responses with similar to70 ps pulse width and a corresponding 3 dB bandwidth of 1.65 GHz.