Regensburg 2022 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 10: Nitrides
HL 10.8: Talk
Monday, September 5, 2022, 17:00–17:15, H34
Temperature dependent electroluminescence spectroscopy on AlGaN-based 235nm far-UVC LEDs with different active region growth temperature — •Paula Vierck, Jakob Höpfner, Martin Guttmann, Marcel Schilling, Luca Sulmoni, Anton Muhin, Tim Wernicke, and Michael Kneissl — Technische Universität Berlin, Institute of Solid State Physics, Berlin, Germany
Light emitting diodes (LEDs) emitting in the far ultraviolet-C (far-UVC) spectral range are promising for applications such as sensing and monitoring of gases, and skin safe disinfection. To improve their external quantum efficiency (EQE), it is crucial to understand the influence of growth parameters on their performance. In this paper, AlGaN-based LEDs emitting around 235 nm were investigated, while their active region growth temperature (Tgrowth) was varied between 900 ∘C and 1100 ∘C. Temperature dependent light output power-current-voltage characteristics (LIV) and spectra were measured on-wafer for temperatures between 100 K and 340 K. An increasing EQE was observed for increasing Tgrowth up to 1060 ∘C with a maximum value of 0.25 % at room temperature. This increase in EQE is attributed to a reduced point defect incorporation at higher active region growth temperatures. This finding is supported by a shift of the EQE vs. temperature maximum from a sample stage temperature of 220 K for an active region growth temperature of 900 ∘C to 260 K for an active region growth temperature of 1060 ∘C indicating an increased radiative recombination efficiency as a consequence of reduced point defect incorporation.