Resonance Raman studies in Cu/sub 2/O. II. The yellow and green excitonic series
Resonance Raman studies in Cu/sub 2/O. II. The yellow and green excitonic series
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Cu/sub 2/O 的共振拉曼研究。
DOI：
10.1103/physrevb.17.4017
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发表时间：
1978
期刊：
影响因子：
--
通讯作者：
Y. Shen
中科院分区：
文献类型：
--
作者：
P. Y. Yu;Y. Shen
多声子模式的共振拉曼散射已在 ${\mathrm{Cu}}_{2}$O 的黄色和绿色激子系列区域中进行了研究。已经观察到大量拉曼模式的共振增强。实验结果通过三种激子-声子散射过程进行了定量解释：（i）黄激子内散射——根据黄色激子的能量，涉及的声子是红外活性${\ensuremath{\Gamma}}_{15}^{\ensuremath{-}}$（660 ${\mathrm{cm}}^{\ensuremath{-}1}$）或${\ensuremath{\Gamma}}_{12}^{\ensuremath{-}}$ (109 ${\mathrm{cm}}^{\ensuremath{-}1}$) 和 ${\ensuremath{\Gamma}}_{15}^{\ensuremath{-}}$ (154 ${\mathrm{cm}}^{\ensuremath{-}1}$)模式； (ii) $2P$绿色激子态和黄色激子连续体之间的激子间散射——负责该散射过程的声子是高能${\ensuremath{\Gamma}}_{15}^{\ensuremath{-}}$模式； (iii) 绿色激子内散射——仅涉及低能量 ${\ensuremath{\Gamma}}_{15}^{\ensuremath{-}}$ 模式。从这些结果中，获得了 ${\mathrm{Cu}}_{2}$O 中黄色和绿色激子通过声子发射的弛豫机制的详细图片。
Resonant Raman scattering of multiphonon modes has been studied in ${\mathrm{Cu}}_{2}$O in the region of its yellow and green excitonic series. Resonant enhancements of a large number of Raman modes have been observed. The experimental results have been interpreted quantitatively in terms of three kinds of exciton-phonon scattering processes: (i) intra-yellow-exciton scattering---depending on the energy of the yellow exciton, the phonons involved are the infrared active ${\ensuremath{\Gamma}}_{15}^{\ensuremath{-}}$ (660 ${\mathrm{cm}}^{\ensuremath{-}1}$) or the ${\ensuremath{\Gamma}}_{12}^{\ensuremath{-}}$ (109 ${\mathrm{cm}}^{\ensuremath{-}1}$) and ${\ensuremath{\Gamma}}_{15}^{\ensuremath{-}}$ (154 ${\mathrm{cm}}^{\ensuremath{-}1}$) modes; (ii) interexciton scattering between the $2P$ green exciton state and yellow excitons continuum---the phonon responsible for this scattering process is the high-energy ${\ensuremath{\Gamma}}_{15}^{\ensuremath{-}}$ mode; and (iii) intra-green-exciton scattering---only the low-energy ${\ensuremath{\Gamma}}_{15}^{\ensuremath{-}}$ mode is involved. From these results a detailed picture of the relaxation mechanisms of the yellow and green excitons in ${\mathrm{Cu}}_{2}$O by emission of phonons is obtained.