Optical and Structural Study of GaN Nanowires Grown by Catalyst-Free MBE: (II) Defect-Related Luminescence and Electron-Beam Irradiation Effects

Published

June 1, 2007

Author(s)

Lawrence H. Robins, Kristine A. Bertness, John G. Barker, Norman A. Sanford, John B. Schlager

Abstract

GaN nanowires grown by catalyst free molecular beam epitaxy were characterized by photoluminescence (PL) and cathodoluminescence (CL) spectroscopy at temperatures from 3 K to 295 K. Both as grown samples, which contained approximately vertically oriented nanowires together with a rough, faceted matrix layer, and dispersions of the nanowires onto other substrates, were examined. The properties of the near band edge (free and shallow donor bound exciton) peaks in the CL and PL spectra, including strain effects, were discussed in a related publication (Part I). Several relatively weak luminescence peaks at energies from 3.45 eV to 3.21 eV were denoted d1 to d6 (in order of decreasing emission energy). The d1 to d6 lines were correlated with a set of defect luminescence lines denoted the Yi lines, whose properties were described in a recent review (M.A. Reshchikov and H. Morkoc, J. Appl. Phys. 97, 061301 (2005)). The Yi lines are ascribed to excitons bound to point defects or impurities, which are in turn localized near extended defects.

Citation

Journal of Applied Physics

Volume

101

Issue

11

Pub Type

Journals

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DOI Link

Keywords

cathodoluminescence, molecular beam epitaxy, nanotechnology, optical spectroscopy, semiconductor nanowires

Citation

Robins, L. , Bertness, K. , Barker, J. , Sanford, N. and Schlager, J. (2007), Optical and Structural Study of GaN Nanowires Grown by Catalyst-Free MBE: (II) Defect-Related Luminescence and Electron-Beam Irradiation Effects, Journal of Applied Physics, [online], https://doi.org/10.1063/1.2736266 (Accessed October 9, 2024)