Berlin 2024 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 52: Nitrides: Devices
HL 52.7: Talk
Friday, March 22, 2024, 11:15–11:30, EW 015
Temperature dependent electroluminescence studies of the influence of the electron blocking layer thickness on the emission characteristics of deep ultraviolet light emitting diodes — •Jakob Höpfner1, Fabio Steyer1, Marcel Schilling1, Anton Muhin1, Tim Wernicke1, and Michael Kneissl1,2 — 1Technische Universität Berlin, Institute of Solid State Physics, Berlin, Germany — 2Ferdinand-Braun-Institut (FBH), Gustav-Kirchhoff-Str. 4, 12489 Berlin, Germany
Earlier studies have shown that a low current injection efficiency (CIE) is partly responsible for the poor external quantum efficiencies (EQE) of AlGaN-based deep ultraviolet light emitting diodes (DUV-LEDs). In particular, the hole injection and the carrier distribution in the AlGaN multi quantum well (MQW) active region is not well understood. In order to get a better insight we have performed temperature dependent electroluminescence (EL) investigations of three-fold AlGaN MQW LEDs with a variation of the electron blocking layer (EBL) thickness. We found an optimal EBL thickness of 12 nm for the highest external quantum efficiency of our DUV-LEDs. Additionaly we observed no voltage penalty by increasing the EBL-thickness. Temperature dependent measurements revealed a difference in high temperature stability with changed electron blocking layer thickness of our devices. These experimental results are also supported by by drift diffusion simulations and enable us to further understand the carrier transport in DUV-LED heterostructures.
Keywords: UV; LED; 233 nm; Electrolumineszenz; temperature