Raman spectroscopy from buried semiconductor interfaces: Structural and electronic properties

Abstract

This review focuses on the analysis of buried semiconductor interfaces by Raman spectroscopy, i.e. inelastic light scattering. Simultaneous access to structural and electronic properties can be obtained by employing phonon Raman scattering, induced by deformation potential, or alternatively by the electric-field induced Fröhlich mechanism, as well as Raman scattering from coupled plasmon-LO-phonon modes. Structural information may comprise intermixing, reactivity, strain and interfacial atomic bond sequences. The main electronic properties derived from Raman spectroscopy are the doping levels of the constituent layers, the interfacial electric field strengths and the free-carrier depletion layer widths. Attention is paid also to the possibility of in situ growth monitoring by Raman spectroscopy. Examples of semiconductor interface analysis are presented for heterovalent interfaces between II-VI and III-V semiconductors, especially ZnSe/GaAs(001) and CdTe/ InSb(001), as well as for heavily strained CdTe monolayers, embedded in a BeTe epilayer on GaAs(001).

Evaluating Phonon Characteristics by Varying the Layer and Interfacial Thickness in Novel Carbon-Based Strained-Layer Superlattices

“…In this context, the Raman scattering spectroscopy (RSS) [10,[45][46][47][48][49][50][51][52][53][54] is considered one of the most trusted techniques for identifying the vibrational characteristics of semiconductor materials. By using RSS, the observed acoustic and optical phonon features in SLs can display strong dependence on the arrangement of their atomic constituents [21,[45][46][47]. While the acoustic part of phonon spectrum is sensitive to the large-scale preparation of SLs [i.e., on the overall periodicity (m, n), capping-and buffer-layer thickness, etc.…”

“…While the acoustic part of phonon spectrum is sensitive to the large-scale preparation of SLs [i.e., on the overall periodicity (m, n), capping-and buffer-layer thickness, etc. ], the optical phonon spectra depend, however, on their unit cells including individual-layer thickness, and interfacial roughness [45][46][47][48][49][50][51][52][53][54]. Previously, several RSS measurements on GaN/Al x Ga 1−x N SLs [10,21] have provided strong evidence of the graded alloy interface regions of the order of ~2 nm.…”

Combined Computational and Experimental Study of CdSeS/ZnS Nanoplatelets: Structural, Vibrational, and Electronic Aspects of Core–Shell Interface Formation

“…25 Moreover, a ZnS shell keeps the PL efficiency of CdSe NPLs high and dramatically increases it with time, resulting in brighter NPLs than for the original CdSe quantum dots. 25 Raman spectroscopy is a sensitive method for the structural characterization of semiconductor interfaces and has proven to give valuable insights into interfacial strain, 26 which can significantly influence exciton localization in the case of core− shell nanocrystals. 27 Because the detailed experimental measurement of Raman spectra of nanostructures is especially challenging, 28,29 simulated Raman spectra are particularly useful for linking structural changes to vibrational modes at core−shell interfaces.…”