Strain Sensitivity in the Nitrogen 1s NEXAFS Spectra of Gallium Nitride

TL;DR

This paper investigates how lattice strain in gallium nitride affects its Nitrogen 1s NEXAFS spectra, revealing a proportional relationship and interpreting it through density functional theory calculations.

Contribution

It demonstrates a direct correlation between lattice strain and spectral features in GaN NEXAFS, supported by theoretical calculations, advancing understanding of strain effects in semiconductor spectroscopy.

Findings

Spectroscopic variation is proportional to strain in GaN thin films.

Density functional theory explains the origin of strain-induced spectral changes.

Strong linear dichroism observed due to anisotropic crystal structure.

Abstract

The Nitrogen 1s near edge X-ray absorption fine structure (NEXAFS) of gallium nitride (GaN) shows a strong natural linear dichroism that arises from its anisotropic wurtzite structure. An additional spectroscopic variation arises from lattice strain in epitaxially grown GaN thin films. This variation is directly proportional to the degree of strain for some spectroscopic features. This strain variation is interpreted with the aid of density functional theory calculations.