Excitonic optical nonlinearities and transport in the layered compound semiconductor GaSe.
Excitonic optical nonlinearities and transport in the layered compound semiconductor GaSe.
复制标题
层状化合物半导体 GaSe 中的激子光学非线性和输运。
DOI：
10.1103/physrevb.51.16651
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Hvam
中科院分区：
文献类型：
--
作者：
Mizeikis;Lyssenko;Erland;Hvam
低温下GaSe直接激子吸收区的减相和瞬态光栅实验表明，一维无序激子带内的快速弛豫导致带填充是光学非线性的主要机制。相应地，我们观察到非线性信号随激发密度的蓝移。在平行于GaSe层面的方向上测量的激子扩散常数的温度依赖性表明，温度无关的散射（俘获）和声子散射决定了激子在低温下的迁移率。
Dephasing and transient grating experiments in the direct excitonic absorption region of GaSe at low temperatures show that a fast relaxation within the one-dimensionally disordered excitonic band results in band filling being the dominant mechanism of the optical nonlinearity. Correspondingly, we observe a blueshift of the nonlinear signal with excitation density. The temperature dependence of the exciton diffusion constant measured in directions parallel to the GaSe layer planes indicates that temperature-independent scattering (trapping) and scattering by acoustic phonons determine the exciton mobility at low temperatures.