Charge carrier dynamics in bulk MoS2 crystal studied by transient absorption microscopy
Charge carrier dynamics in bulk MoS2 crystal studied by transient absorption microscopy
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通过瞬态吸收显微镜研究块状 MoS2 晶体中的载流子动力学
DOI：
10.1063/1.4799110
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发表时间：
2013-04-07
影响因子：
3.2
通讯作者：
Zhao, Hui
中科院分区：
文献类型：
--
作者：
Kumar, Nardeep;He, Jiaqi;Zhao, Hui
我们报告了一个瞬态吸收显微镜研究散装二硫化钼晶体在室温下的载流子动力学。电荷载流子注入带间吸收的555 nm脉冲，并通过测量差分反射的时间延迟和空间扫描的660 nm脉冲探测。我们发现谷间转移时间约为0.35 ps，热载流子的能量弛豫时间约为50 ps，载流子寿命为180 ± 20 ps。通过监测载流子的时空动力学，我们获得了热化电子的扩散系数为4.2 ± 0.5 cm 2/s，对应于迁移率为170 ± 20 cm 2/Vs。我们还观察到热载流子的扩散系数随时间变化。
We report a transient absorption microscopy study of charge carrier dynamics in bulk MoS2 crystals at room temperature. Charge carriers are injected by interband absorption of a 555-nm pulse, and probed by measuring differential reflection of a time-delayed and spatially scanned 660-nm pulse. We find an intervalley transfer time of about 0.35 ps, an energy relaxation time of hot carriers on the order of 50 ps, and a carrier lifetime of 180 ± 20 ps. By monitoring the spatiotemporal dynamics of carriers, we obtained a diffusion coefficient of thermalized electrons of 4.2 ± 0.5 cm2/s, corresponding to a mobility of 170 ± 20 cm2/Vs. We also observed a time-varying diffusion coefficient of hot carriers.