Prediction of hot zone-center optical phonons in laser-irradiated molybdenum disulfide with a semiconductor multitemperature model
Prediction of hot zone-center optical phonons in laser-irradiated molybdenum disulfide with a semiconductor multitemperature model
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DOI：
10.1103/physrevb.107.l041407
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发表时间：
2022-06
影响因子：
3.7
通讯作者：
Zherui Han;Peter Sokalski;Li Shi;X. Ruan
中科院分区：
文献类型：
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作者：
Zherui Han;Peter Sokalski;Li Shi;X. Ruan
先前的多温度模型（MTM）解决声子温度的偏振水平和测量已经发现显着的非平衡在不同的声子偏振在激光照射的石墨烯和金属。在这里，我们开发了一个特定的超导体MTM（SC-MTM），包括电子-空穴对的产生，扩散和重组，并表明声子极化水平模型不会产生可观察到的基于极化的非平衡激光辐照二硫化钼（MoS$_2$）。与此相反，明显的非平衡预测之间的区心光学声子和其他模式。动量为基础的非平衡比被发现增加与减小激光光斑尺寸和与基板的相互作用。这一发现与理解二维光电子器件中的能量弛豫过程和热输运的拉曼测量有关。
Previous multitemperature model (MTM) resolving phonon temperatures at the polarization level and measurements have uncovered remarkable nonequilibrium among different phonon polarizations in laser irradiated graphene and metals. Here, we develop a semiconductor-specific MTM (SC-MTM) by including electron-hole pair generation, diffusion, and recombination, and show that a phonon polarization-level model does not yield observable polarization-based nonequilibrium in laser-irradiated molybdenum disulfide (MoS$_2$). In contrast, appreciable nonequilibrium is predicted between zone-center optical phonons and the other modes. The momentum-based nonequilibrium ratio is found to increase with decreasing laser spot size and interaction with a substrate. This finding is relevant to the understanding of the energy relaxation process in two-dimensional optoelectronic devices and Raman measurements of thermal transport.