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arXiv · 1401.5732

Temperature Renormalization of Optical Spectra of Monolayer MoS2

Ryan Soklaski·Yufeng Liang·Changjian Zhang·Haining Wang·Farhan Rana·Li Yang
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Abstract

Newly measured optical absorption and photoluminescence spectra reveal substantial frequency shifts of both exciton and trion peaks as monolayer MoS2 is cooled from 363 K to 4 K. First-principles simulations using the GW-Bethe-Salpeter Equation approach satisfactorily reproduce these frequency shifts by incorporating many-electron interactions and the thermal expansion of the in-plane lattice constant. Studying these temperature effects in monolayer MoS2 is crucial for rectifying the results of room-temperature experiments with the previous predictions of zero-temperature-limit simulations. Moreover, we estimate that the thermal expansion coefficient of monolayer MoS2 is around 25% less than that of bulk counterpart by tracking the frequency shifts of the exciton or trion peaks in optical spectra. This may serve as a convenient way to estimate thermal expansion coefficients of general two-dimensional chalcogenides.

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Ryan Soklaski, Yufeng Liang, Changjian Zhang, Haining Wang, Farhan Rana, Li Yang. 2014-01-22. Temperature Renormalization of Optical Spectra of Monolayer MoS2. https://doi.org/10.1063/1.4878098

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