Understanding the Nature of Superlattice Interface Modes by Multiphonon Raman Scattering

Le résumé fourni par la source

Multiphonon (MP) Raman spectra involving only the macroscopic interface (IF) modes in extra-short-period (GaAs)4/(AlAs)2 AB/CB-type superlattice (SL) and the localized microscopic interface (LMIF) mode in (CdSe)4/(ZnTe)8 AB/CD SL are reported. The MP Raman spectra involving only IF modes are attributed to the ability of electrons in the wells to penetrate into the barrier. The MP features of the LMIF mode were found to be completely different from those of the longitudinal optical (LO) bulk-like mode in the same sample. These novel MP features of the LMIF mode have been successfully explained by the anharmonic decay theory of localized modes of defects, suggesting that the interface of AB/CD-type SLs can be considered as defects in SLs. In contrast, the wavenumber and intensity behaviour of the MP spectra of the IF modes are similar to those of the LO modes, but the dependence of the linewidths on the order of the IF modes is reminescent of that of the LMIF mode. These behaviours indicate that the IF modes contain characteristics of both the bulk-like LO mode and the LMIF mode.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.