Enhanced excitonic features in an anisotropic ReS₂/WSe₂ heterostructure

Abstract

A ReS2/WSe2 heterostructure and its polarization resolved PL spectra.

Singlet‐exciton optics and phonon‐mediated dynamics in oligoacene semiconductor crystals

“…Around these two distinct exciton valleys, we can use the Wannier equation to calculate the exciton binding energies and wave functions (see Supporting Information for more details) 53 . The resulting binding energies $$E^b_{ij, \mu }$$ and excitonic wave functions resemble those of a 2D hydrogen atom with $$\mu \in (1s, 2s, 2p_x, \ldots )$$, 24 albeit anisotropic, owing to the anisotropy of the underlying crystal structure 54 . In addition to the exciton states formed around the direct bandgap in the crystal, there are also momentum‐dark excitons formed when the electron and hole originate from different valleys, 55,56 as shown in the excitonic dispersion in Figure 1(c).…”

“…53 The resulting binding energies E b ij,𝜇 and excitonic wave functions resemble those of a 2D hydrogen atom with 𝜇 ∈ (1s, 2s, 2p x , …), 24 albeit anisotropic, owing to the anisotropy of the underlying crystal structure. 54 In addition to the exciton states formed around the direct bandgap in the crystal, there are also momentum-dark excitons formed when the electron and hole originate from different valleys, 55,56 as shown in the excitonic dispersion in Figure 1(c). The separation between the minima of the MM and ΓΓ excitons is known as the DS, and originates from the coupling between the two symmetrically distinct molecules in the unit cell.…”

Synthesis of a large area ReS2 thin film by CVD for in-depth investigation of resistive switching: effects of metal electrodes, channel width and noise behaviour

“…X 1 gives a direct optical band gap at 1.26 eV, which is consistent with the bandgap of ReS 2 as per the literature. 27,28 Interestingly, X 3 has comparatively higher energy but the lowest intensity when compared to X 1 and X 2 . This renders a possibility that it might correspond to the excited states of the Rydberg series of the excitons X 1 and X 2 .…”

Microscopic modelling of phonon-mediated exciton propagation in organic semiconductors

“…We find exciton binding energies of ∼ 800 meV owing to the large effective mass of the underlying band structure. 18,25 The excitons are well-confined to individual tetracene layers due to the weak interlayer coupling within the crystal 15,18,26 and hence we use a screened 2D Coulomb potential to derive the excitonic binding energies. 19 To microscopically describe the excitonic propagation, we calculate the spatio-temporal evolution of the exciton distribution 27,28 (cf.…”