Paper
26 February 2016 Optical investigation of microscopic defect distribution in semi-polar (1-101 and 11-22) InGaN light-emitting diodes
Author Affiliations +
Abstract
Near-field scanning optical microscopy was applied to investigate the spatial variations of extended defects and their effects on the optical quality for semi-polar (1-101) and (11-22) InGaN light emitting diodes (LEDs). (1-101) and (11-22) oriented InGaN LEDs emitting at 450-470 nm were grown on patterned Si (001) 7° offcut substrates and m-sapphire substrates by means of nano-epitaxial lateral overgrowth (ELO), respectively. For (1-101) structures, the photoluminescence (PL) at 85 K from the near surface c+ wings was found to be relatively uniform and strong across the sample. However, emission from the c- wings was substantially weaker due to the presence of high density of threading dislocations (TDs) and basal plane stacking faults (BSFs) as revealed from the local PL spectra. In case of (11-22) LED structures, near-field PL intensity correlated with the surface features and the striations along the direction parallel to the c-axis projection exposed facets where the Indium content was higher as deduced from shift in the PL peak energy.
© (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Shopan Hafiz, Nicolas Andrade, Morteza Monavarian, Natalia Izyumskaya, Saikat Das, Fan Zhang, Vitaliy Avrutin, Hadis Morkoç, and Ümit Özgür "Optical investigation of microscopic defect distribution in semi-polar (1-101 and 11-22) InGaN light-emitting diodes", Proc. SPIE 9748, Gallium Nitride Materials and Devices XI, 974828 (26 February 2016); https://doi.org/10.1117/12.2213908
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Light emitting diodes

Gallium nitride

Indium gallium nitride

Near field scanning optical microscopy

Near field optics

Indium

Scanning electron microscopy

Back to Top