Low-temperature photocarrier dynamics in monolayer MoS2
Low-temperature photocarrier dynamics in monolayer MoS2
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DOI：
10.1063/1.3636402
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发表时间：
2011-09-05
影响因子：
4
通讯作者：
Schueller, C.
中科院分区：
文献类型：
--
作者：
Korn, T.;Heydrich, S.;Schueller, C.
MoS2 的能带结构很大程度上取决于层数，最近观察到单层 MoS2 从间接带隙半导体到直接带隙半导体的转变。因此，即使在室温下，单层 MoS2 也能成为有效的光致发光发射体。在这里，我们报告了对通过剥离制备的单层 MoS2 薄片的扫描拉曼和温度依赖性以及时间分辨光致发光测量。我们观察到在低温下出现两个不同的光致发光峰。低温下的光载流子复合发生在几皮秒的时间尺度上，但随着温度的升高，观察到寿命较长的组分的双指数光致发光衰减。 (C) 2011 年美国物理研究所。 [doi:10.1063/1.3636402]
The band structure of MoS2 strongly depends on the number of layers, and a transition from indirect to direct-gap semiconductor has been observed recently for a single layer of MoS2. Single-layer MoS2 therefore becomes an efficient emitter of photoluminescence even at room temperature. Here, we report on scanning Raman and on temperature-dependent, as well as time-resolved photoluminescence measurements on single-layer MoS2 flakes prepared by exfoliation. We observe the emergence of two distinct photoluminescence peaks at low temperatures. The photocarrier recombination at low temperatures occurs on the few-picosecond timescale, but with increasing temperatures, a biexponential photoluminescence decay with a longer-lived component is observed. (C) 2011 American Institute of Physics. [doi:10.1063/1.3636402]