Giant enhancement of exciton diffusivity in two-dimensional semiconductors

Two-dimensional (2D) semiconductors bear great promise for application in optoelectronic devices, but the low diffusivity of excitons stands as a notable challenge for device development. Here, we demonstrate that the diffusivity of excitons in monolayer MoS2 can be improved from 1.5 ± 0.5 to 22.5 ± 2.5 square centimeters per second with the presence of trapped charges. This is manifested by a spatial expansion of photoluminescence when the incident power reaches a threshold value to enable the onset of exciton Mott transition. The trapped charges are estimated to be in a scale of 1010 per square centimeter and do not affect the emission features and recombination dynamics of the excitons. The result indicates that trapped charges provide an attractive strategy to screen exciton scattering with phonons and impurities/defects. Pointing towards a new pathway to control exciton transport and many-body interactions in 2D semiconductors.

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Possible weakening of the many-body interactions in the organic quasi-two-dimensional metal α-(BETS)2NH4Hg(SCN)4

Journal of Experimental and Theoretical Physics ◽

10.1134/s1063776109100124 ◽

2009 ◽

Vol 109 (4) ◽

pp. 664-666 ◽

Cited By ~ 4

Author(s):

S. I. Pesotskiĭ ◽

R. B. Lyubovskiĭ ◽

M. V. Kartsovnik ◽

W. Biberacher ◽

N. D. Kushch ◽

...

Keyword(s):

Two Dimensional ◽

Many Body ◽

The Many ◽

Many Body Interactions

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Probing many-body interactions in a disordered semiconductor quantum well with electronic two-dimensional Fourier transform spectroscopy

10.1117/12.840125 ◽

2010 ◽

Author(s):

Zheng Sun ◽

Thomas W. Jarvis ◽

Xiaoqin Li ◽

Mikhail Erementchouk ◽

Michael N. Leuenberger

Keyword(s):

Fourier Transform ◽

Quantum Well ◽

Fourier Transform Spectroscopy ◽

Two Dimensional ◽

Many Body ◽

Semiconductor Quantum Well ◽

Many Body Interactions

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Many-Body Interactions in Semiconductors Probed by Optical Two-Dimensional Fourier Transform Spectroscopy

Physical Review Letters ◽

10.1103/physrevlett.96.057406 ◽

2006 ◽

Vol 96 (5) ◽

Cited By ~ 181

Author(s):

Xiaoqin Li ◽

Tianhao Zhang ◽

Camelia N. Borca ◽

Steven T. Cundiff

Keyword(s):

Fourier Transform ◽

Fourier Transform Spectroscopy ◽

Two Dimensional ◽

Many Body ◽

Many Body Interactions

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Probing the microscopic origin of many-body interactions in semiconductors using optical two-dimensional Fourier transform spectroscopy

2005 Quantum Electronics and Laser Science Conference ◽

10.1109/qels.2005.1548909 ◽

2005 ◽

Author(s):

T. Zhang ◽

X. Li ◽

C.N. Borea ◽

S.T. Cundiff

Keyword(s):

Fourier Transform ◽

Fourier Transform Spectroscopy ◽

Two Dimensional ◽

Many Body ◽

Many Body Interactions ◽

Microscopic Origin

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Highly Enhanced Many-Body Interactions in Anisotropic 2D Semiconductors

Accounts of Chemical Research ◽

10.1021/acs.accounts.7b00504 ◽

2018 ◽

Vol 51 (5) ◽

pp. 1164-1173 ◽

Cited By ~ 19

Author(s):

Ankur Sharma ◽

Han Yan ◽

Linglong Zhang ◽

Xueqian Sun ◽

Boqing Liu ◽

...

Keyword(s):

Many Body ◽

2D Semiconductors ◽

Many Body Interactions

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Phonon-assisted processes in the ultraviolet-transient optical response of graphene

npj 2D Materials and Applications ◽

10.1038/s41699-019-0131-5 ◽

2019 ◽

Vol 3 (1) ◽

Cited By ~ 1

Author(s):

Dino Novko ◽

Marko Kralj

Keyword(s):

Dominant Role ◽

Chemical Doping ◽

Two Dimensional ◽

Many Body ◽

Time Resolved ◽

Electron Phonon Interaction ◽

Spectral Changes ◽

Two Dimensional Materials ◽

Many Body Interactions

AbstractMany recent experiments investigated potential and attractive means of modifying many-body interactions in two-dimensional materials through time-resolved spectroscopy techniques. However, the role of ultrafast phonon-assisted processes in two-dimensional systems is rarely discussed in depth. Here, we investigate the role of electron–phonon interaction in the transient optical absorption of graphene by means of first-principles methods. It is shown at equilibrium that the phonon-assisted transitions renormalize significantly the electronic structure. As a result, absorption peak around the Van-Hove singularity broadens and redshifts by ~100 meV. In addition, temperature increase and chemical doping are shown to notably enhance these phonon-assisted features. In the photoinduced transient response, we obtain spectral changes in close agreement with the experiments, and we associate them to the strong renormalization of occupied and unoccupied $$\pi$$π bands, which predominantly comes from the coupling with the zone-center $${E}_{2g}$$E2g optical phonon. Our estimation of the Coulomb interaction effects shows that the phonon-assisted processes can have a dominant role even in the subpicosecond regime.

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