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Updated: Apr 11, 2026

High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy
Published on: June 28, 2016
Electron-phonon interactions in MoS2 probed with ultrafast two-dimensional visible/far-infrared spectroscopy
Xunmin Guo1, Hailong Chen1, Xiewen Wen1
1Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005-1892, USA.
Abstract:
An ultrafast two-dimensional visible/far-IR spectroscopy based on the IR/THz air biased coherent detection method and scanning the excitation frequencies is developed. The method allows the responses in the far-IR region caused by various electronic excitations in molecular or material systems to be observed in real time. Using the technique, the relaxation dynamics of the photo-excited carriers and electron/phonon coupling in bulk MoS2 are investigated. It is found that the photo-generation of excited carriers occurs within two hundred fs and the relaxation of the carriers is tens of ps. The electron-phonon coupling between the excitations of electrons and the phonon mode E1u of MoS2 is also directly observed. The electron excitation shifts the frequency of the phonon mode 9 cm(-1) higher, resulting in an absorption peak at 391 cm(-1) and a bleaching peak at 382 cm(-1). The frequency shift diminishes with the relaxation of the carriers.
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