Radiative defects in GaN nanocolumns: Correlation with growth conditions and sample morphology

Journal Article · Mon Feb 21 00:00:00 EST 2011 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.3556643· OSTI ID:21518295

Lefebvre, P; Fernandez-Garrido, S; Grandal, J; Ristic, J; Sanchez-Garcia, M -A; Calleja, E ^[1]

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1. Instituto de Sistemas Optoelectronicos y Microtecnologia, Universidad Politecnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain)

Low-temperature photoluminescence is studied in detail in GaN nanocolumns (NCs) grown by plasma-assisted molecular beam epitaxy under various conditions (substrate temperature and impinging Ga/N flux ratio). The relative intensities of the different emission lines, in particular those related to structural defects, appear to be correlated with the growth conditions, and clearly linked to the NC sample morphology. We demonstrate, in particular, that all lines comprised between 3.10 and 3.42 eV rapidly lose intensity when the growth conditions are such that the NC coalescence is reduced. The well-known line around 3.45 eV, characteristic of GaN NC samples, shows, however, a behavior that is exactly the opposite of the other lines, namely, for growth conditions leading to reduced NC coalescence, this line tends to become more prominent, thus proving to be intrinsic to individual GaN NCs.

• OSTI ID: 21518295
• Journal Information: Applied Physics Letters, Vol. 98, Issue 8; Other Information: DOI: 10.1063/1.3556643; (c) 2011 American Institute of Physics; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COALESCENCE
CORRELATIONS
CRYSTAL DEFECTS
CRYSTAL GROWTH
GALLIUM NITRIDES
MOLECULAR BEAM EPITAXY
NANOSTRUCTURES
PHOTOLUMINESCENCE
PLASMA
SEMICONDUCTOR MATERIALS
SUBSTRATES
CRYSTAL GROWTH METHODS
CRYSTAL STRUCTURE
EMISSION
EPITAXY
GALLIUM COMPOUNDS
LUMINESCENCE
MATERIALS
NITRIDES
NITROGEN COMPOUNDS
PHOTON EMISSION
PNICTIDES