Large‐Area, Solar‐Blind, Sub‐250 nm Detection AlGaN Avalanche Photodiodes Grown on AlN Substrates. Issue 6 (10th March 2022) - Reddy, Pramod
Abstract : Herein, Al‐rich AlGaN‐based avalanche photodiodes (APDs) grown on single crystal AlN substrates high ultraviolet‐C sensitivity for λ < 200 nm are fabricated, while exhibiting blindness to λ > 250 nm. A maximum quantum efficiency of 68% and peak gain of 320 000 are estimated resulting in a figure of merit of ≈220 000 in devices with ϕ = 100 μm. As expected, a decrease in gain with increase in device size is observed and a gain of ≈20 000 is estimated in devices with ϕ = 400 μm. Overall, two orders of magnitude higher performance are observed in APDs on single crystal AlN substrates compared to those on sapphire. Abstract : Herein, Al‐rich AlGaN‐based avalanche photodiodes grown on single crystal AlN substrates are demonstrated, exhibiting solar blindness and high ultraviolet‐C sensitivity for λ < 200 nm operating at <150 V. A maximum quantum efficiency of 68% and peak gain of 320 000 are achieved resulting in a figure of merit of ≈220 000 in devices with ϕ = 100 μm.