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HL: Fachverband Halbleiterphysik

HL 44: Nitrides: Devices

HL 44.5: Vortrag

Donnerstag, 30. März 2023, 16:15–16:30, POT 112

UVC-LEDs grown on HTA-AlN templates with low dislocation densities and high Si doping for strain management — •Tim Mampe¹, Sarina Graupeter¹, Giulia Cardinali¹, Sylvia Hagedorn², Tim Wernicke¹, Markus Weyers², and Michael Kneissl^1,2 — ¹Technische Universität Berlin, Institute of Solid State Physics, Hardenbergstraße 36, 10623 Berlin, Germany — ²Ferdinand-Braun-Institut (FBH),Gustav-Kirchhoff-Straße 4, 12489 Berlin, Germany

High temperature annealing (HTA) of AlN layers reduces the threading dislocation density of such layers on sapphire substrates below 10⁹ cm⁻² enabling UVC-LEDs with improved efficiencies. However, the HTA AlN-layers are under high compressive strain after cooling down, which can lead to strain relaxation and defect formation during further LED heterostructure growth. The in-plane lattice constant can be increased by growing a Si-doped AlN layer on HTA-AlN. In this work we investigate the influence of such an AlN:Si-layer on the growth of UVC-LEDs emitting at 265nm on AlN/sapphire substrates with silicon doped as well as undoped AlN layer and different sapphire offcut angles (0.1^∘, 0.2^∘, 0.5^∘). We will discuss the morphology as well as the strain state of AlN and AlGaN layers as well as the electro-optical properties of multi quantum-well (MQW) and LED structures.