Influences of screw dislocations on electroluminescence of AlGaN/AlN-based UVC LEDs

Dong Liu; Sang June Cho; Huilong Zhang; Corey R. Carlos; Akhil R. K. Kalapala; Jeongpil Park; Jisoo Kim; Rafael Dalmau; Jiarui Gong; Baxter Moody; Xudong Wang; John D. Albrecht; Weidong Zhou; Zhenqiang Ma

doi:10.1063/1.5108743

AIP Advances (Aug 2019)

Influences of screw dislocations on electroluminescence of AlGaN/AlN-based UVC LEDs

Dong Liu,
Sang June Cho,
Huilong Zhang,
Corey R. Carlos,
Akhil R. K. Kalapala,
Jeongpil Park,
Jisoo Kim,
Rafael Dalmau,
Jiarui Gong,
Baxter Moody,
Xudong Wang,
John D. Albrecht,
Weidong Zhou,
Zhenqiang Ma

Affiliations

Dong Liu: Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
Sang June Cho: Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
Huilong Zhang: Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
Corey R. Carlos: Department of Material Science Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
Akhil R. K. Kalapala: Department of Electrical Engineering, University of Texas at Arlington, 500 South Cooper Street, Arlington, Texas 76019, USA
Jeongpil Park: Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
Jisoo Kim: Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
Rafael Dalmau: HexaTech, Inc., 991 Aviation Parkway, Suite 800, Morrisville, North Carolina 27560, USA
Jiarui Gong: Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
Baxter Moody: HexaTech, Inc., 991 Aviation Parkway, Suite 800, Morrisville, North Carolina 27560, USA
Xudong Wang: Department of Material Science Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
John D. Albrecht: Department of Electrical and Computer Engineering, Michigan State University, 428 S. Shaw Lane, East Lansing, Michigan 48824, USA
Weidong Zhou: Department of Electrical Engineering, University of Texas at Arlington, 500 South Cooper Street, Arlington, Texas 76019, USA
Zhenqiang Ma: Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA

DOI: https://doi.org/10.1063/1.5108743
Journal volume & issue: Vol. 9, no. 8
pp. 085128 – 085128-6

Abstract

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We investigated two types of threading dislocations in high Al-composition Al0.55Ga0.45N/AlN multiple quantum well (MQW) structures grown on AlN substrate for electrically injected deep ultraviolet light-emitting diodes (LEDs). The surface morphology and defects electrical characteristics of the MQW LED structures were examined via conductive atomic force microscopy (CAFM). We found that the disparity between photoluminescence (PL) and electroluminescence (EL) spectra in terms of light emission output and wavelength shift are attributed to the existence of the surface hillocks, especially to the ones that have open-core dislocations. The open-core dislocations form current leakage paths through their defect states and the composition inhomogeneity (i.e., Ga rich) at the dislocation sites are responsible for the light emission at longer wavelengths.

Published in AIP Advances

ISSN: 2158-3226 (Online)
Publisher: AIP Publishing LLC
Country of publisher: United States
LCC subjects: Science: Physics
Website: http://aipadvances.aip.org/

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