Electron-interface-phonon interactions and its ternary effects on in ZnS/CdxZn1-xS core-shell heterostructures

Wen Deng Huang,Ya Jie Ren,Zhaolin Yuan,Li Fu Bao,Ke Zhou

doi:10.1063/1.5064721

Abstract

Within the framework of dielectric continuum mode (DCM), random-element isodisplacement model (REIM) and standard quantization procedure, the electron-interface-phonon interactions and its ternary effects in ZnS/CdxZn1-xS core-shell heterostructures are investigated. The dispersion curves, the electron-phonon couplings and its ternary mixed crystal effects of interface optical (IO) phonons in ZnS/CdxZn1-xS core-shell heterostructures are calculated and discussed in detail. The results indicate that the IO phonons are more dispersive in low quantum number. With the increase of the cadmium element concentration, the IO phonon frequencies decrease linearly in high frequency range (HF-range), and decreases non-linearly in low frequency range (LF-range). The numerical results also indicate that the IO phonons with lower quantum number play a significant role in electron-phonon interactions. The electron-phonon coupling strengths increase linearly in HF-range, and increase non-linearly in LF-range with the increasing cadmium element concentration. The IO phonons in HF-range have prominent contributions to electron-phonon interactions.Within the framework of dielectric continuum mode (DCM), random-element isodisplacement model (REIM) and standard quantization procedure, the electron-interface-phonon interactions and its ternary effects in ZnS/CdxZn1-xS core-shell heterostructures are investigated. The dispersion curves, the electron-phonon couplings and its ternary mixed crystal effects of interface optical (IO) phonons in ZnS/CdxZn1-xS core-shell heterostructures are calculated and discussed in detail. The results indicate that the IO phonons are more dispersive in low quantum number. With the increase of the cadmium element concentration, the IO phonon frequencies decrease linearly in high frequency range (HF-range), and decreases non-linearly in low frequency range (LF-range). The numerical results also indicate that the IO phonons with lower quantum number play a significant role in electron-phonon interactions. The electron-phonon coupling strengths increase linearly in HF-range, and increase non-linearly in LF-range with the incr...

Highlights

INTRODUCTIONThe importance of phonons and their interactions is well known to many physical processes in these confined quantum hetero-structures
With the development of the techniques for the crystals growth, all kinds of low dimensional semiconductor nano-structures can be fabricated
Three dispersion curves are in low frequency range (LF-range, ωT,CdS < ω < ωT,ZnS), three dispersion curves are in high frequency range (HF-range, ωL,CdS < ω < ωL,ZnS)

Summary

INTRODUCTION

The importance of phonons and their interactions is well known to many physical processes in these confined quantum hetero-structures. We will investigate the properties of interface optical (IO) phonons, electron-IO phonon interaction and its ternary mixed crystal effects in ZnS/CdxZn1-xS core-shell heterostructures. TERNARY EFFECTS ON INTERFACE OPTICAL PHONONS IN ZnS/Cdx Zn1-x S CORE-SHELL HETEROSTRUCTURES

The LO and TO phonons in Cdx Zn1-x S ternary crystal with cubic structure

NUMERICAL RESULTS AND DISCUSSIONS

CONCLUSION