Resonant Raman scattering spectra in a ZnCdSe/ZnSe structure with a quantum well

2020-01-05 04:54:33

quantum ZnSe scattering phonons ZnCdSe

责任者: Kaibyshev, V.Kh.;Travnikov, V.V.;Davydov, V.Yu. 单位: Ioffe Physicotech. Inst., Acad. of Sci., St. Petersburg, Russia 来源出处: Physics of The Solid State(Phys. Solid State (Russia)),2003/07/,45(7):1374-8 摘要: Resonance Raman scattering (RS) spectra of a ZnCdSe/ZnSe sample containing a single quantum well and quantum well-based open nanowires were studied at T=300 K. The longitudinal optical (LO) phonons involved in the formation of the observed spectra of the quantum-well and nanowire regions differ noticeably in energy. The LO phonon energies in the structures under study were calculated taking into account the compositional effect (doping of Cd into ZnSe) and biaxial strain. When excited in the exciton resonance region, RS is shown to occur via free (extended) excitonic states with the involvement of LO phonons of the ZnCdSe strained layer with final wave vectors near the Brillouin zone center. When excited below the excitonic resonance in the ZnCdSe layer, resonance scattering via localized exciton states provides a noticeable contribution to the observed RS lines. Because of the finite size of a localized state, phonons with large wave vectors are involved in these scattering processes. The RS lines produced under excitation in the excitonic region of the thick barrier layers are due to scattering from the ZnSe barrier phonons 关键词: Brillouin zones;cadmium compounds;excitons;II-VI semiconductors;internal stresses;localised modes;localised states;nanowires;phonons;Raman spectra;semiconductor quantum wells;wide band gap semiconductors;zinc compounds;resonant Raman scattering spectra;ZnCdSe/ZnSe structure;quantum well;open nanowires;quantum well based open nanowires;optical phonons;nanowire regions;compositional effect;Cd doping;biaxial strain;exciton resonance region;excitonic states;ZnCdSe strained layer;wave vectors;Brillouin zone center;resonance scattering;localized exciton states;finite size;scattering process;excitation;barrier layers;ZnSe barrier phonons;longitudinal optical phonons energy;300 K;ZnCdSe-ZnSe