Momentum-resolved hot electron dynamics at the 2H-MoS2 surface
Momentum-resolved hot electron dynamics at the 2H-MoS2 surface
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DOI：
10.1103/physrevb.94.205406
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发表时间：
2016-11-07
影响因子：
3.7
通讯作者：
Bauer, M.
中科院分区：
文献类型：
--
作者：
Hein, P.;Stange, A.;Bauer, M.
利用时间和角度分辨光电子能谱（trARPES）研究了光激发2 H-MoS 2导带中的热电子动力学。近紫外光激发后高达150 fs的动量依赖性上升时间和几百fs量级的衰减时间使我们能够定位导带能量景观中的光吸收区域，以及跟踪热电子弛豫到最低能量状态。导带最小值最终在大约1 ps内被减少，尽管剩余的人口仍然高达15 ps的最大调查泵浦探测延迟。的快速人口减少通道的存在下，从散装二硫化钼与全光学方法进行的实验结果不同。然而，它符合单层二硫化钼的最新研究结果。我们将这种相似性归因于缺陷和表面状态是相当相关的近表面的电子动力学散装二硫化钼，在一个trARPES实验中探测。
Time- and angle-resolved photoelectron spectroscopy (trARPES) is employed to study hot electron dynamics in the conduction band of photoexcited 2H-MoS2. Momentum-dependent rise times of up to 150 fs after near-ultraviolet photoexcitation and decay times of the order of several-hundred fs allow us to locate areas of light absorption in the conduction-band energy landscape as well as to track the relaxation of hot electrons into the lowest-energy states. The conduction-band minima are finally depopulated within approximate to 1 ps, although a residual population remains up to the maximum investigated pump-probe delay of 15 ps. The presence of the fast depopulation channel differs from the results of experiments of bulk MoS2 performed with all-optical methods. It conforms, however, with recent findings for monolayer MoS2. We attribute this similarity to defect and surface states being of considerable relevance for the near-surface electron dynamics of bulk MoS2, as probed in a trARPES experiment.