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Nanoscale Characterization of V-Defect in InGaN/GaN QWs LEDs Using Near-Field Scanning Optical Microscopy
- Source :
- Nanomaterials, Vol 9, Iss 4, p 633 (2019)
- Publication Year :
- 2019
- Publisher :
- MDPI AG, 2019.
-
Abstract
- The size of the V-defects in the GaN/InGaN-based quantum wells blue light-emitting diode (LED) was intentionally modified from 50 nm to 300 nm. High resolution photoluminescence and electroluminescence of a single large V-defect were investigated by near-field scanning optical microscopy. The current distribution along the {10-11} facets of the large defect was measured by conductive atomic force microscopy. Nearly 20 times the current injection and dominant emission from bottom quantum wells were found in the V-defect compared to its vicinity. Such enhanced current injection into the bottom part of quantum wells through V-defect results in higher light output power. Reduced external quantum efficiency droops were achieved due to more uniform carrier distribution. The un-encapsulated fabricated chip shows light output power of 172.5 mW and 201.7 mW at 400 mA, and external quantum efficiency drop of 22.3% and 15.4% for the sample without and with large V-defects, respectively. Modified V-defects provide a simple and effective approach to suppress the efficiency droop problem that occurs at high current injection, while improving overall quantum efficiency.
- Subjects :
- V-defect
InGaN/GaN QWs
LEDs
NSOM
quantum efficiency
Chemistry
QD1-999
Subjects
Details
- Language :
- English
- ISSN :
- 20794991
- Volume :
- 9
- Issue :
- 4
- Database :
- Directory of Open Access Journals
- Journal :
- Nanomaterials
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.8d643d980ca9462aa5d91b017af5a048
- Document Type :
- article
- Full Text :
- https://doi.org/10.3390/nano9040633