Electronic Band Structure of Wurtzite GaP Nanowires via Resonance Raman Spectroscopy

TL;DR

This study uses resonance Raman spectroscopy to analyze the electronic band structure of defect-free wurtzite GaP nanowires, revealing energy states and band energies at the Gamma point, and refining theoretical models.

Contribution

It provides experimental measurements of band energies and symmetries in wurtzite GaP nanowires, aiding the refinement of theoretical band structure calculations.

Findings

Resonance at specific energies indicates valence and conduction band symmetries.

Zero temperature band energies and splitting energies were extrapolated.

Results help improve theoretical models of wurtzite GaP band structure.

Abstract

Raman measurements are performed on defect-free wurzite GaP nanowires. Resonance Raman measurements are carried out over the excitation energy range between 2.19 and 2.71 eV. Resonances at 2.38 eV and 2.67 eV of the E1(LO) mode and at 2.67 eV of the A1(LO) are observed. The presence of these intensity resonances clearly demonstrates the existence of energy states with Gamma_9hh and Gamma_7V (Gamma_7C) symmetries of the valence (conduction) band and allows to measure WZ phase GaP band energies at the Gamma point. In addition, we have investigated temperature dependent resonant Raman measurements, which allowed us to extrapolate the zero temperature values of Gamma point energies, along with the crystal field and spin-orbit splitting energies. Above results provide a feedback for refining available theoretical calculations to derive the correct wurtzite III-V semiconductor band structure.