Spectroscopic investigation of native defects induced electron-phonon coupling in GaN nanowires

TL;DR

This study investigates how native defects in GaN nanowires influence electron-phonon coupling, using spectroscopic techniques to analyze defect-related variations in optical and electronic properties.

Contribution

It provides detailed spectroscopic evidence of native defect-induced electron-phonon coupling in GaN nanowires, linking defect types to optical and electronic behavior.

Findings

Variation in Ga/N ratios correlates with native defect types.

Native defects affect carrier density and mobility.

Recombination processes involve defect-related phonon interactions.

Abstract

The integration of advanced optoelectronic properties in nanoscale devices of group III nitride can be realized by understanding the coupling of charge carriers with optical excitations in these nanostructures. The native defect induced electron-phonon coupling in GaN nanowires are reported using various spectroscopic studies. The GaN nanowires having different native defects are grown in atmospheric pressure chemical vapor deposition technique. X-ray photoelectron spectroscopic analysis revealed the variation of Ga/N ratios in nanowires having possible native defects, with respect to their growth parameters. The analysis of characteristics features of electron-phonon coupling in Raman spectra show the variations in carrier density and mobility with respect to the native defects in unintentionally doped GaN nanowires. The radiative recombination of donor acceptor pair transitions and the corresponding LO phonon replicas observed in photoluminescence studies further emphasize the role of native defects in electron-phonon coupling.