Interband Optical Transitions in Extremely Anisotropic Semiconductors. I. Bound and Unbound Exciton Absorption

Shinada, Masaki; Sugano, Shigeru

doi:10.1143/jpsj.21.1936

Cited by 499 publications

(162 citation statements)

References 7 publications

Supporting

Mentioning

153

Contrasting

Order By: Relevance

“…The exciton binding energy can therefore be estimated by multiplying this splitting by a factor of 9/8, which is valid for a ideal two-dimensional exciton. 17 Thus, we find a binding energy of the 1sHH exciton of Ϸ9 meV. This value is slightly smaller than what we find for an isolated 80 Å quantum well ͑11.5 meV͒ and is related to the superlattice effect.…”

Section: Dcontrasting

confidence: 63%

See 1 more Smart Citation

Interwell excitons in GaAs superlattices

et al. 1996

View full text Add to dashboard Cite

Section: Dcontrasting

confidence: 63%

“…is the exciton quantization number. 17 Hence, the ratio of the diamagnetic shifts of the 1s and the 2s excitons equals 9. The interwell exciton has approximately half the binding energy of the 1sHH exciton and we would expect to find a ratio of the interwell and 1sHH diamagnetic shifts near 2.…”

Section: Dmentioning

confidence: 99%

Interwell excitons in GaAs superlattices

et al. 1996

View full text Add to dashboard Cite

“…in a hydrogenic series with n = 1, 2... (Klingshirn, 2007;Shinada and Sugano, 1966). As clearly shown in reflection spectroscopy (Chernikov et al, 2014;He et al, 2014), the exciton states in ML WSe 2 and WS 2 , for example, deviate from this simple dependence, see Fig.…”

Section: Exciton and Continuum States In Optics And Transportmentioning

confidence: 81%

“…This can be illustrated, e.g., in comparative studies of the absolute energies of exciton resonances for monolayer samples placed in different dielectric environments, effectively tuning both the exciton binding energy and the free particle bandgap Raja et al, 2017;Stier et al, 2016b). As a final point, the Coulomb interaction leads to a significant enhancement of the continuum absorption, which is predicted to extend many times of E B into the band (Haug and Koch, 2009;Shinada and Sugano, 1966).…”

Section: A Neutral Excitons: Direct and Exchange Coulomb Interactionmentioning

confidence: 99%

Excitons in atomically thin transition-metal dichalcogenides

et al. 2014

View full text Add to dashboard Cite

Atomically thin materials such as graphene and monolayer transition metal dichalcogenides (TMDs) exhibit remarkable physical properties resulting from their reduced dimensionality and crystal symmetry. The family of semiconducting transition metal dichalcogenides is an especially promising platform for fundamental studies of two-dimensional (2D) systems, with potential applications in optoelectronics and valleytronics due to their direct band gap in the monolayer limit and highly efficient light-matter coupling. A crystal lattice with broken inversion symmetry combined with strong spin-orbit interactions leads to a unique combination of the spin and valley degrees of freedom. In addition, the 2D character of the monolayers and weak dielectric screening from the environment yield a significant enhancement of the Coulomb interaction. The resulting formation of bound electron-hole pairs, or excitons, dominates the optical and spin properties of the material. Here we review recent progress in our understanding of the excitonic properties in monolayer TMDs and lay out future challenges. We focus on the consequences of the strong direct and exchange Coulomb interaction, discuss exciton-light interaction and effects of other carriers and excitons on electron-hole pairs in TMDs. Finally, the impact on valley polarization is described and the tuning of the energies and polarization observed in applied electric and magnetic fields is summarized.

show abstract

“…The weaker screening leads thereby to an increase of the excitonic binding energy. (ii) An increased electron-hole overlap in the reduced dimensionality leads also to a stronger binding energy [in the purely 2D limit, the binding energy for a hydrogenic system is increased by a factor of 4 compared to the 3D case [21] ]. At the same time, reduced dimensionality and reduced screening lead to an increased electron-electron correlation and thereby to an increase of the quasiparticle gap [22].…”

mentioning

confidence: 99%

Excitons in Boron Nitride Nanotubes: Dimensionality Effects

2006

View full text Add to dashboard Cite

We show that the optical absorption spectra of boron nitride (BN) nanotubes are dominated by strongly bound excitons. Our first-principles calculations indicate that the binding energy for the first and dominant excitonic peak depends sensitively on the dimensionality of the system, varying from 0.7 eV in bulk hexagonal BN via 2.1 eV in the single sheet of BN to more than 3 eV in the hypothetical 2; 2 tube. The strongly localized nature of this exciton dictates the fast convergence of its binding energy with increasing tube diameter towards the sheet value. The absolute position of the first excitonic peak is almost independent of the tube radius and system dimensionality. This provides an explanation for the observed ''optical gap'' constancy for different tubes and bulk hexagonal BN.

show abstract

Interband Optical Transitions in Extremely Anisotropic Semiconductors. I. Bound and Unbound Exciton Absorption

Cited by 499 publications

References 7 publications

Interwell excitons in GaAs superlattices

Interwell excitons in GaAs superlattices

Excitons in atomically thin transition-metal dichalcogenides

Excitons in Boron Nitride Nanotubes: Dimensionality Effects

Contact Info

Product

Resources

About