Cathodoluminescence as an effective probe of carrier transport and deep level defects in droop-mitigating InGaN/GaN quantum well heterostructures

Journal Article · 29 January 2019 · Applied Physics Express

DOI: https://doi.org/10.7567/1882-0786/ab0341 · OSTI ID:1502800

Zhao, Zhibo ^[1]; Singh, Akshay  ^[1]; Chesin, Jordan ^[1]; Armitage, Rob ^[2]; Wildeson, Isaac ^[2]; Deb, Parijat ^[2]; Armstrong, Andrew ^[3]; Kisslinger, Kim ^[4]; Stach, Eric A.  ^[4]; Gradečak, Silvija ^[1]

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1. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Materials Science and Engineering
2. Lumileds LLC, San Jose, CA (United States)
3. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
4. Brookhaven National Lab. (BNL), Upton, NY (United States). Center for Functional Nanomaterials

Commercial InGaN/GaN light emitting diodes continue to suffer from efficiency droop at high current densities, and urgently require enhanced structural-optical toolsets for active region characterization. We measure delayed (tens of seconds) cathodoluminescence which is influenced by carrier transport and deep level defects. Further, we observe that drops in efficiency are not correlated with quantum well (QW) width fluctuations. To explain the rise dynamics, we propose a model involving filling of deep level defects and simultaneous reduction of built-in field within the multi-QW active region. These measurements yield insights into carrier transport, efficiency-reducing defects, and QW band structure.

• Research Organization: Brookhaven National Lab. (BNL), Upton, NY (United States); Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lumileds LLC, San Jose, CA (United States); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
• Sponsoring Organization: USDOE Office of Science (SC); USDOE National Nuclear Security Administration (NNSA); USDOE Office of Energy Efficiency and Renewable Energy (EERE), Building Technologies Office (EE-5B); National Science Foundation (NSF) (United States)
• Grant/Contract Number: SC0012704; NA0003525; EE0007136
• OSTI ID: 1502800
• Report Number(s): BNL--211427-2019-JAAM
• Journal Information: Applied Physics Express, Journal Name: Applied Physics Express Journal Issue: 3 Vol. 12; ISSN 1882-0778
• Publisher: Japan Society of Applied PhysicsCopyright Statement
• Country of Publication: United States
• Language: English