Optical and Structural Study of GaN Nanowires Grown by Catalyst Free MBE: (I) Near Band Edge Luminescence and Strain Effects
Lawrence H. Robins, Kristine A. Bertness, John G. Barker, Norman A. Sanford, John B. Schlager
GaN nanowires with diameters of 50 nm to 250 nm, 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 dominant features of the low temperature PL and CL spectra were near band edge peaks ascribed to A ( 3.479 eV) and B ( 3.484 eV) free excitons, and A excitons bound to neutral, shallow donor impurities (D0XA centers, 3.472 eV). The peak emission energies of the D0XA centers in the nanowire samples are very similar to literature results for free standing, 30 m to 380 m thick, quasi substrate layers; this similarity implies that the average strain in the nanowires is
, Bertness, K.
, Barker, J.
, Sanford, N.
and Schlager, J.
Optical and Structural Study of GaN Nanowires Grown by Catalyst Free MBE: (I) Near Band Edge Luminescence and Strain Effects, Journal of Applied Physics, [online], https://doi.org/10.1063/1.2736264
(Accessed December 2, 2023)