Exciton-exciton and exciton-carrier scattering in GaSe
Exciton-exciton and exciton-carrier scattering in GaSe
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GaSe 中的激子-激子和激子-载流子散射
DOI：
10.1103/physrevb.11.2243
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发表时间：
1975
影响因子：
3.7
通讯作者：
J. Voitchovsky
中科院分区：
文献类型：
--
作者：
A. Mercier;J. Voitchovsky
研究了仅含有低杂质浓度的 GaSe 单晶在高激发强度下的光致发光。在高激发下出现四条线，其中一条对应于受激发射。这些谱线的特性被描述为激发强度、4.2 至 300 K 之间的温度以及激发能量的函数。 4.2 K 处的两条线位于自由直接激子下方 4 和 35 meV，分别归因于激子载流子散射导致自发发射和受激发射。另外两条线位于激子下方 15 和 20 meV。它们对应于两种不同的激子-激子散射过程。第一个激子从基态 n= 1 散射到激发态 n= 2，而另一个激子则辐射复合。在第二个过程中，其中一个激子解离，在各自的能带中产生电子空穴对，另一个激子发射光子。这些线随温度和激发强度的变化可以通过现象学理论来解释。
An investigation is presented of the photoluminescence at high excitation intensities, in monocrystals of GaSe which contain only low impurity concentrations. Four lines appear at high excitation, one of which corresponds to stimulated emission. The properties of these lines are described as functions of excitation intensity, temperature between 4.2 and 300 K, and of excitation energy. Two lines, which at 4.2 K lie 4 and 35 meV below the free direct exciton, are attributed to exciton-carrier scattering giving rise to spontaneous and stimulated emission, respectively. The two other lines are located 15 and 20 meV below the exciton. They correspond to two different exciton-exciton scattering processes. In the first, an exciton is scattered from the ground state n= 1 to the excited state n= 2, whereas the other recombines radiatively. In the second process, one of the excitons dissociates giving rise to an electron-hole pair in their respective bands, the other one emits a photon. The shifts of these lines with temperature and excitation intensity are interpreted by phenomenological theory.