Analysis of structural defects with the chemical composition of rGO/GaN nanocomposites using Raman spectroscopy

Abstract

In this work, Raman spectroscopy was employed to examine the interface properties of chemically synthesized Gallium Nitride decorated reduced graphene oxide (rGO/GaN) nanocomposites. From the Raman analyses, a redshift of 6.68 cm−1 was detected in the E2 (high) phonon mode of GaN which indicates that GaN has tensile stress in the rGO network. As calculated from intensity ratios of the D to G band, there was the detection of fewer structural defects in the rGO/GaN nanocomposites while increasing the amount of GaN from 1 to 20 wt%. Moreover, from the analysis of the width of the 2D peak, less stacking of graphene sheets was discovered with more association of GaN nanoparticles. Photoluminescence (PL) studies revealed the absolute intensity corresponding to both the near band edge (NBE) GaN and blue PL emission of rGO increases with more incorporation of GaN. This implies that the radiative charge carrier recombination on rGO/GaN surface was increased thus improving the optical quality of the rGO/GaN nanocomposites. rGO/GaN nanocomposites have been reported to be useful in energy storage applications and can further be extended to applications such as LEDs, solar cells, photodetectors, UV photodiodes, and gas sensors in the prospect.