Open AccessExtraction of absorption coefficients from as-grown GaN nanowires on opaque substrates using all-optical method
Author(s) -
Rahul Jayaprakash,
Debo Ajagunna,
S. Germanis,
M. Androulidaki,
K. Tsagaraki,
A. Georgakilas,
N. T. Pelekanos
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.019555
Subject(s) - nanowire , materials science , opacity , absorption (acoustics) , substrate (aquarium) , attenuation coefficient , optics , crystal (programming language) , optoelectronics , permittivity , extraction (chemistry) , composite material , dielectric , chemistry , oceanography , physics , computer science , programming language , geology , chromatography
We demonstrate a new all-optical method to measure absorption coefficients in any family of as-grown nanowires, provided they are grown on a substrate having considerable difference in permittivity with the nanowire-air matrix. In the case of high crystal quality, strain-free GaN nanowires, grown on Si (111) substrates, the extracted absorption coefficients do not exhibit any enhancement compared to bulk GaN values, unlike relevant claims in the literature. This could be attributed to the relatively small diameters, short heights, and high densities of our nanowire arrays.