Tunable electronic structure in gallium chalcogenide van der Waals compounds
Tunable electronic structure in gallium chalcogenide van der Waals compounds
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镓硫族化物范德华化合物中的可调谐电子结构
DOI：
10.1103/physrevb.100.165112
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发表时间：
2019
影响因子：
3.7
通讯作者：
Rotenberg, Eli
中科院分区：
文献类型：
--
作者：
Shevitski, Brian;Ulstrup, Søren;Koch, Roland J.;Cai, Hui;Tongay, Sefaattin;Moreschini, Luca;Jozwiak, Chris;Bostwick, Aaron;Zettl, Alex;Rotenberg, Eli
过渡金属单硫族化合物是一类具有电子带隙的二维材料，对材料厚度和化学成分高度敏感。在这里，我们利用角分辨光电发射光谱研究了GaSe中电子激发光谱的可调性。通过原位钾沉积和形成合金化合物来修饰材料的电子结构。我们发现钾剂量样品在价带最大值（VBM）周围的色散发生了实质性的变化。观察到的带色散类似于单个四层的带色散，并且符合从体的直接间隙特性到单层GaSe的间接间隙特性的转变。在与硫合金化后，我们观察到从AB到堆叠的相变。合金化还导致VBM的刚性能量向更高的结合能转移，这与发光中的蓝移有关。硫合金化时带隙的增加似乎不会明显改变VBM的色散或特性，这意味着可以在保持其显著电子性能的同时设计这些材料的带隙。
Transition-metal monochalcogenides comprise a class of two-dimensional materials with electronic band gaps that are highly sensitive to material thickness and chemical composition. Here, we explore the tunability of the electronic excitation spectrum in GaSe by using angle-resolved photoemission spectroscopy. The electronic structure of the material is modified byin situpotassium deposition as well as by formingalloy compounds. We find that potassium-dosed samples exhibit a substantial change of the dispersion around the valence-band maximum (VBM). The observed band dispersion resembles that of a single tetralayer and is consistent with a transition from the direct-gap character of the bulk to the indirect-gap character expected for monolayer GaSe. Upon alloying with sulfur, we observe a phase transition from AB tostacking. Alloying also results in a rigid energy shift of the VBM towards higher binding energies, which correlates with a blueshift in the luminescence. The increase of the band gap upon sulfur alloying does not appear to change the dispersion or character of the VBM appreciably, implying that it is possible to engineer the gap of these materials while maintaining their salient electronic properties.
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影响因子：
56.9
作者：
Ohta, Taisuke;Bostwick, Aaron;Rotenberg, Eli
通讯作者：
Rotenberg, Eli
影响因子：
3.7
作者：
Mucha-Kruczynski, M.;Tsyplyatyev, O.;Rotenberg, Eli
通讯作者：
Rotenberg, Eli
GaSe1−xSx 系列中的多型相变
影响因子：
3.3
作者：
J. Terhell;V. Brabers;G. Egmond
通讯作者：
G. Egmond
影响因子：
41.2
作者：
Watanabe, K;Taniguchi, T;Kanda, H
通讯作者：
Kanda, H
影响因子：
29.4
作者：
Cai, Hui;Soignard, Emmanuel;Tongay, Sefaattin
通讯作者：
Tongay, Sefaattin