Optically Discriminating Carrier-Induced Quasiparticle Band Gap and Exciton Energy Renormalization in Monolayer<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi>MoS</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math>

Yao, Kaiyuan; Yan, Aiming; Kahn, Salman; Süslü, Aslıhan; Liang, Yufeng; Barnard, Edward S.; Tongay, Sefaattin; Zettl, Alex; Borys, Nicholas J.; Schuck, P. James

doi:10.1103/physrevlett.119.087401

Cited by 89 publications

(116 citation statements)

References 58 publications

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“…[95], was neglected in our calculations. Therefore, we conclude that our quasiparticle gap is in reasonable agreement with the experimental value of 2.78(2) eV [96].…”

Section: Tions Using a Finite Field Approachsupporting

confidence: 91%

Dielectric-dependent hybrid functionals for heterogeneous materials

Zheng

Govoni

Galli

2019

Phys. Rev. Materials

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We derive a dielectric-dependent hybrid functional which accurately describes the electronic properties of heterogeneous interfaces and surfaces, as well as those of three-and two-dimensional bulk solids. The functional, which does not contain any adjustable parameter, is a generalization of self-consistent hybrid functionals introduced for homogeneous solids, where the screened Coulomb interaction is defined using a spatially varying, local dielectric function. The latter is determined self-consistently using density functional calculations in finite electric fields. We present results for the band gaps and dielectric constants of 3D and 2D bulk materials, and band offsets for interfaces, showing an accuracy comparable to that of GW calculations.

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“…[95], was neglected in our calculations. Therefore, we conclude that our quasiparticle gap is in reasonable agreement with the experimental value of 2.78(2) eV [96].…”

Section: Tions Using a Finite Field Approachsupporting

confidence: 91%

Dielectric-dependent hybrid functionals for heterogeneous materials

Zheng

Govoni

Galli

2019

Phys. Rev. Materials

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“…Due to the reduced dielectric screening and relatively heavy particle band masses, few-layered transition-metal dichalcogenide (TMDs) form tightly bound electron-hole pairs (excitons) with binding energies up to hundreds of meV, which is much larger than that in conventional bulk semiconductors. [1][2][3] The strongly bound excitons produce a variety of interesting multiparticle excitations such as charged excitons (trions), biexcitons, and exciton-trion complexes. [3][4][5] Because of efficient Coulomb interactions, few-layered TMDs are strongly interacting systems even in high carrier densities, thus, they provide an ideal vehicle to study fundamental many-body physics, such as band-gap renormalization and the Mott transition.…”

Section: Introductionmentioning

confidence: 99%

“…[3][4][5] Because of efficient Coulomb interactions, few-layered TMDs are strongly interacting systems even in high carrier densities, thus, they provide an ideal vehicle to study fundamental many-body physics, such as band-gap renormalization and the Mott transition. 2,[6][7][8] Carrier doping allows us to modulate the band structure of TMDs and manipulate their properties. By increasing the doping in few-layered TMDs, carriers can occupy the phase space of the conduction (valence) band at the K/K' points leading to the Pauli blocking effect, as originated from the Pauli exclusive principle.…”

Section: Introductionmentioning

confidence: 99%

“…6 A band-gap renormalization of over 150 meV and an exciton binding energy as large as 790 meV have also been demonstrated in monolayer molybdenum disulfide (MoS 2 ) through photoluminescence excitation (PLE). 2 With intense optical pulses, a Mott transition from excitons to free carriers has been observed accompanied by a huge band-gap renormalization. 7 To date, most of the experiments involving the many-body effects in TMDs have been performed at cryogenic temperature (50-80 K).…”

Section: Introductionmentioning

confidence: 99%

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Many-body effects in doped WS2 monolayer quantum disks at room temperature

et al. 2019

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Due to strong Coulomb interactions, reduced screening effects, and quantum confinement, transition-metal dichalcogenide (TMD) monolayer quantum disks (MQDs) are expected to exhibit large exciton binding energy, which is beneficial for the investigation of many-body physics at room temperature. Here, we report the first observations of room-temperature many-body effects in tungsten disulfide (WS 2 ) MQDs by both optical measurements and theoretical studies. The band-gap renormalization in WS 2 MQDs was about 250 ± 15 meV as the carrier density was increased from 0.6(±0.2) × 10 12 to 8.3(±0.2) × 10 12 cm −2 . We observed a striking exciton binding energy as large as 990 ± 30 meV at the lowest carrier density, which is larger than that in WS 2 monolayers. The huge exciton binding energy in WS 2 MQDs is attributed to the extra quantum confinement in the lateral dimension. The band-gap renormalization and exciton binding energies are explained using efficient reduced screening. On the basis of the Debye screening formula, the Mott density in WS 2 MQDs was estimated to be~3.95 × 10 13 cm −2 . Understanding and manipulation of the many-body effects in two-dimensional materials may open up new possibilities for developing exciton-based optoelectronic devices.npj 2D Materials and Applications (2019) 3:46 ; https://doi.

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“…Electronic properties of such systems are shown to be highly sensitive to external perturbation that introduces excess electron or hole concentrations. For instance, electrostatic and chemical doping techniques were successfully utilized in order to tune optical absorption as well as plasmon and exciton energies in graphene-based materials [3][4][5][6][7][8][9], transitions metal dichalcogenides [10][11][12][13][14][15][16], and corresponding van-der-Waals heterostructures [17,18].…”

Section: Introductionmentioning

confidence: 99%

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

Novko

Kralj

2019

npj 2D Mater Appl

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Many 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 around 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 π bands, which predominantly comes from the coupling with the zone-center 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. arXiv:1911.04826v1 [cond-mat.mtrl-sci]

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Optically Discriminating Carrier-Induced Quasiparticle Band Gap and Exciton Energy Renormalization in MonolayerMoS2

Cited by 89 publications

References 58 publications

Dielectric-dependent hybrid functionals for heterogeneous materials

Dielectric-dependent hybrid functionals for heterogeneous materials

Many-body effects in doped WS2 monolayer quantum disks at room temperature

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

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