Regensburg 2022 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 10: Nitrides

HL 10.7: Vortrag

Montag, 5. September 2022, 16:45–17:00, H34

Influence of the AlGaN MQW growth temperature on the performance characteristics of DUV-LEDs with emission at 235 nm — •Marcel Schilling, Norman Susilo, Giulia Cardinali, Anton Muhin, Frank Mehnke, Tim Wernicke, Michael Kneissl, and Jakob Höpfner — Technische Universität Berlin, Institute of Solid State Physics, Hardenbergstraße 36, 10623 Berlin, Germany

The realization of efficient deep ultraviolet light emitting diodes (DUV-LEDs) with emission wavelength near 235 nm is very challenging as the photon energy is very close to the band gap of AlN. For AlGaN layers with high Al mole fractions point defects like vacancies and impurities are easily incorporated during metal organic vapor phase epitaxy (MOVPE). Deep levels in the energy band gap associated with these point defects play a decisive role in non-radiative carrier recombination and consequently low internal quantum efficiency (IQE) of DUV-LEDs. Therefore, the understanding of the generation of point defects during the growth of high Al containing AlGaN layers is crucial for the development of efficient DUV-LEDs. In this study the influence of the AlGaN MQW growth temperature on the point defect density in 235 nm DUV-LEDs is investigated. DUV-LEDs were grown by MOVPE with MQW growth temperatures between 850 ^∘C and 1100 ^∘C. Temperature dependent PL measurements show that the point defect incorporation might be controlled with the MOVPE growth temperature. Electroluminescence measurements showed an increase in optical output power from 5 µW up to 300 µW at 20 mA for 235 nm DUV-LEDs for increasing MQW growth temperatures from 850^∘C up to 1020 ^∘C.