1. High gain, large area, and solar blind avalanche photodiodes based on Al-rich AlGaN grown on AlN substrates.
- Author
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Reddy, Pramod, Hayden Breckenridge, M., Guo, Qiang, Klump, Andrew, Khachariya, Dolar, Pavlidis, Spyridon, Mecouch, Will, Mita, Seiji, Moody, Baxter, Tweedie, James, Kirste, Ronny, Kohn, Erhard, Collazo, Ramon, and Sitar, Zlatko
- Subjects
AVALANCHE photodiodes ,BREAKDOWN voltage ,SCREW dislocations ,DISLOCATION density ,SINGLE crystals - Abstract
We demonstrate large area (25 000 μm
2 ) Al-rich AlGaN-based avalanche photodiodes (APDs) grown on single crystal AlN substrates operating with differential (the difference in photocurrent and dark current) signal gain of 100 000 at 90 pW (<1 μW cm−2 ) illumination with very low dark currents <0.1 pA at room temperature under ambient light. The high gain in large area AlGaN APDs is attributed to a high breakdown voltage at 340 V, corresponding to very high breakdown fields ∼9 MV cm−1 as a consequence of low threading and screw dislocation densities < 103 cm−2 . The maximum charge collection efficiency of 30% was determined at 255 nm, corresponding to the bandgap of Al0.65 Ga0.35 N, with a response of 0.06 A/W. No response was detected for λ > 280 nm, establishing solar blindness of the device. [ABSTRACT FROM AUTHOR]- Published
- 2020
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