论文标题
由极端紫外线瞬态吸收光谱捕获的多层WSE2中的载体和声子动力学
Carrier and Phonon Dynamics in Multilayer WSe2 captured by Extreme Ultraviolet Transient Absorption Spectroscopy
论文作者
论文摘要
多层WSE2膜中的载体和声子动力学由W N6,7，W O2,3和SE M4,5边缘（30-60 eV）处的极端紫外线（XUV）瞬态吸收（TA）光谱捕获。在宽带光泵脉冲之后，XUV探针直接报告了光学激发孔的职业和声子诱导的带状率化。通过与密度函数理论计算进行比较，XUV由于孔引起的XUV瞬态吸收在W o3边缘下方鉴定出来，而SE M4,5边缘的信号由声子动力学主导。其中，提取了0.4 PS孔松弛时间，1.5 PS载体重组时间和1.7 PS声子加热时间。单个实验中孔和声子诱导的信号的采集可以促进对电子与声子动力学之间的相关性的研究。此外，可以进一步扩展对来自不同元素的信号的同时观察，以探索多层和合金中的光化学过程，从而为其在电子，光催化剂和纺纱型中的应用提供关键信息。
Carrier and phonon dynamics in a multilayer WSe2 film are captured by extreme ultraviolet (XUV) transient absorption (TA) spectroscopy at the W N6,7, W O2,3, and Se M4,5 edges (30-60 eV). After the broadband optical pump pulse, the XUV probe directly reports on occupations of optically excited holes and phonon-induced band renormalizations. By comparing with density functional theory calculations, XUV transient absorption due to holes are identified below the W O3 edge whereas signals at the Se M4,5 edges are dominated by phonon dynamics. Therein, 0.4 ps hole relaxation time, 1.5 ps carrier recombination time, and 1.7 ps phonon heating time are extracted. The acquisition of hole and phonon-induced signals in a single experiment can facilitate the investigation of the correlations between electron and phonon dynamics. Furthermore, the simultaneous observation of signals from different elements can be further extended to explore photochemical processes in multilayers and alloys, thereby providing key information for their applications in electronics, photocatalysts, and spintronics.
