Near-forward Raman scattering by bulk and surface phonon-polaritons in the model percolation-type ZnBeSe alloy

TL;DR

This paper investigates bulk and surface phonon-polaritons in a ZnBeSe alloy using near-forward Raman scattering, revealing a three-mode behavior and advancing understanding beyond the traditional two-mode approximation through contour modeling.

Contribution

It introduces a refined three-mode model for phonon-polaritons in ZnBeSe alloys, supported by contour modeling of Raman signals, surpassing the conventional two-mode approximation.

Findings

Identification of a three-mode behavior in the alloy's phonon-polaritons.

Successful contour modeling of Raman signals for bulk and surface modes.

Enhanced understanding of phonon-polariton modes in zincblende alloys.

Abstract

We study the bulk and surface phonon-polaritons of the Zn0.67Be0.33Se zincblende alloy by near-forward Raman scattering. The short (Be-Se) bond exhibits a distinct percolation doublet in the conventional backscattering Raman spectra, corresponding to a three-mode behavior in total [1(Zn-Se),2(Be-Se)] for Zn0.67Be0.33Se. This offers an opportunity to achieve a refined understanding of the phonon-polariton modes of a zincblende alloy beyond the current two-mode approximation, corresponding to a [1(Zn-Se),1(Be-Se)] description in the present case. The discussion is supported by contour modeling of the Raman signals of the multi-mode bulk and surface phonon-polaritons within the formalism of the linear dielectric response.