skip to main content

SciTech ConnectSciTech Connect

Title: Dual-polarity GaN micropillars grown by metalorganic vapour phase epitaxy: Cross-correlation between structural and optical properties

Self-assembled catalyst-free GaN micropillars grown on (0001) sapphire substrates by metal organic vapor phase epitaxy are investigated. Transmission electron microscopy, as well as KOH etching, shows the systematic presence of two domains of opposite polarity within each single micropillar. The analysis of the initial growth stages indicates that such double polarity originates at the micropillar/substrate interface, i.e., during the micropillar nucleation, and it propagates along the micropillar. Furthermore, dislocations are also generated at the wire/substrate interface, but bend after several hundreds of nanometers. This leads to micropillars several tens of micrometers in length that are dislocation-free. Spatially resolved cathodoluminescence and microphotoluminescence show large differences in the optical properties of each polarity domain, suggesting unequal impurity/dopant/vacancy incorporation depending on the polarity.
Authors:
 [1] ;  [2] ; ; ; ; ;  [1] ;  [3]
  1. CRHEA-CNRS, Rue Bernard Grégory, F-06560 Valbonne (France)
  2. (UNS), 28 Ave. Valrose, 06103 Nice (France)
  3. Faculté des Sciences de Saint Jérôme—CP2M, Ave. Escadrille Normandie Niemen, 13397 Marseille (France)
Publication Date:
OSTI Identifier:
22273566
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 15; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CATHODOLUMINESCENCE; CORRELATIONS; DISLOCATIONS; ETCHING; GALLIUM NITRIDES; INTERFACES; OPTICAL PROPERTIES; ORGANOMETALLIC COMPOUNDS; PHOTOLUMINESCENCE; POTASSIUM HYDROXIDES; SAPPHIRE; SUBSTRATES; TRANSMISSION ELECTRON MICROSCOPY; VACANCIES; VAPOR PHASE EPITAXY