Structural and luminescence properties of GaN nanowires grown using cobalt phthalocyanine as catalyst

Catalyst free methods have usually been employed to avoid any catalyst induced contamination for the synthesis of GaN nanowires with better transport and optical properties. Here, we have used a catalytic route to grow GaN nanowires, which show good optical quality. Structural and luminescence prope...

Full description

Saved in:
Bibliographic Details
Published in:Journal of applied physics 2015-12, Vol.118 (22)
Main Authors: Yadav, Shivesh, Rodríguez-Fernández, Carlos, de Lima, Mauricio M., Cantarero, Andres, Dhar, Subhabrata
Format: Article
Language:English
Subjects:
Applied physics
Catalysis
Catalysts
Chemical synthesis
Cobalt
Defects
Luminescence
Nanowires
Optical properties
Photoluminescence
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Catalyst free methods have usually been employed to avoid any catalyst induced contamination for the synthesis of GaN nanowires with better transport and optical properties. Here, we have used a catalytic route to grow GaN nanowires, which show good optical quality. Structural and luminescence properties of GaN nanowires grown by vapor-liquid-solid technique using cobalt phthalocyanine as catalyst are systematically investigated as a function of various growth parameters such as the growth temperature and III/V ratio. The study reveals that most of the nanowires, which are several tens of microns long, grow along [101¯0] direction. Interestingly, the average wire diameter has been found to decrease with the increase in III/V ratio. It has also been observed that in these samples, defect related broad luminescence features, which are often present in GaN, are completely suppressed. At all temperatures, photoluminescence spectrum is found to be dominated only by a band edge feature, which comprises of free and bound excitonic transitions. Our study furthermore reveals that the bound excitonic feature is associated with excitons trapped in certain deep level defects, which result from the deficiency of nitrogen during growth. This transition has a strong coupling with the localized vibrational modes of the defects.
ISSN:0021-8979
1089-7550
DOI:10.1063/1.4937159