The influence of threading dislocations propagating through an AlGaN UVC LED

Cameron, Douglas and Edwards, Paul R. and Mehnke, Frank and Kusch, Gunnar and Sulmoni, Luca and Schilling, Marcel and Wernicke, Tim and Kneissl, Michael and Martin, Robert W. (2022) The influence of threading dislocations propagating through an AlGaN UVC LED. Applied Physics Letters, 120 (16). 162101. ISSN 0003-6951 (

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During the epitaxy of AlGaN on sapphire for deep UV emitters, significant lattice mismatch leads to highly strained heterojunctions and the formation of threading dislocations. Combining cathodoluminescence, electron beam induced current and x-ray microanalysis reveal that dislocations with a screw component permeate through a state-of-the-art UVC LED heterostructure into the active region and perturb their local environment in each layer as growth progresses. In addition to acting as non-radiative recombination centers, these dislocations encourage high point defect densities and three-dimensional growth within their vicinity. We find that these point defects can add parasitic recombination pathways and compensate intentional dopants.