Two-dimensional correlation analysis of the time-resolved photoluminescence spectra of gallium nitride nanowires

Abstract

Principal component analysis based two-dimensional (PCA2D) correlation spectroscopy combined with the eigenvalue manipulating transformation (EMT) technique by lowering the power of a set of eigenvalues associated with the original data has been employed to interpret the time-resolved photoluminescence spectra of gallium nitride (GaN) nanowires. PCA2D correlation spectra with EMT operation successfully extracted the substantial contribution of minor components, by emphasizing the neutral-acceptor-bound exciton band and surface-related state band. Upon application of PCA2D correlation analysis in conjunction with the self-modeling curve resolution technique, we were able to not only resolve the spectra and determine the sequence of spectral changes but also extract the individual spectra, which had not been possible from a simple examination of the original 1D spectra. (C) 2007 Elsevier B.V. All rights reserved.