Anomalous features of resonant hyper-Raman scattering in CuBr quantum dots: Evid

2019-10-10 08:35:16

scattering LO DOTS phonon exciton

责任者: Inoue, K.;Yamanaka, A.;Toba, K.;Baranov, A.V.;Onushchenko, A.A.;Fedorov, A.V. 单位: Res. Inst. for Electron. Sci., Hokkaido Univ., Sapporo, Japan 来源出处: Physical Review B (Condensed Matter)(Phys. Rev. B, Condens. Matter (USA)),15 Sept. 1996,54(12):8321-4 摘要: A resonant hyper-Raman scattering signal has been successfully observed in CuBr quantum dots of a weak-confinement regime. It is found that up to fifth-order LO-phonon scattering signals appear in a two-photon resonance with the lowest confined state of the Z12, S exciton, and that the observed order N depends on the two-photon energy 2ℏω1 for the excitation in such a way that it conforms to the equation N⩽(2ℏω1-Eedge)/ℏωLO, with ℏωLO, and Eedge being energies of the LO phonon and the absorption edge, respectively. The anomalous result observed indicates that coupled states of the Wannier exciton and the LO phonon are rather good elementary excitations in these dots 关键词: copper compounds;nanostructured materials;phonon-exciton interactions;Raman spectra;semiconductor doped glasses;semiconductor materials;semiconductor quantum dots;two-photon spectra;resonant hyper-Raman scattering;CuBr quantum dots;exciton-phonon-coupled states;weak-confinement regime;fifth-order LO-phonon scattering signals;two-photon resonance;confined state;S exciton;LO phonon;absorption edge;nanocrystals;Wannier exciton;elementary excitations;glass matrix;CuBr