Avalanche multiplication in AlGaN-based heterostructures for the ultraviolet spectral range

• Published in: Applied physics letters Vol. 112; no. 15
• Main Authors: Hahn, L., Fuchs, F., Kirste, L., Driad, R., Rutz, F., Passow, T., Köhler, K., Rehm, R., Ambacher, O.
• Format: Journal Article
• Language: English
• Published: 09-04-2018
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.5022660

AlxGa1-xN based avalanche photodiodes grown on sapphire substrate with Al-contents of x = 0.65 and x = 0.60 have been examined under back- and frontside illumination with respect to their avalanche gain properties. The photodetectors suitable for the solar-blind ultraviolet spectral regime show avalanche gain for voltages in excess of 30 V reverse bias in the linear gain mode. Devices with a mesa diameter of 100 μm exhibit stable avalanche gain below the break through threshold voltage, exceeding a multiplication gain of 5500 at 84 V reverse bias. A dark current below 1 pA can be found for reverse voltages up to 60 V.