Related papers: Exciton band structure in two-dimensional material…
We theoretically investigate the binding energy and electron-hole (e-h) overlap of excitonic states confined at the interface between two-dimensional materials with type-II band alignment, i.e., with lowest conduction and highest valence…
The electronic bandstructure of a solid is a collection of allowed bands separated by forbidden bands, revealing the geometric symmetry of the crystal structures. Comprehensive knowledge of the bandstructure with band parameters explains…
Metal monochalcogenide GaSe is a classic layered semiconductor that has received increasing research interest due to its highly tunable electronic and optical properties for ultrathin electronics applications. Despite intense research…
The properties of excitons, or correlated electron-hole pairs, are of paramount importance to optoelectronic applications of materials. A central component of exciton physics is the electron-hole interaction, which is commonly treated as…
Hexagonal boron nitride (hBN) has been attracting great attention because of its strong excitonic effects. Taking into account few-layer systems, we investigate theoretically the effects of the number of layers on quasiparticle energies,…
Exciton instability in graphene bilayer systems is studied in the case of a short-ranged Coulomb interaction and a finite voltage difference between the layers. Self-consistent exciton gap equations are derived and solved numerically and…
We present a generalized hydrogen model for the binding energies ($E_B$) of excitons in two-dimensional (2D) materials that sheds light on the fundamental differences between excitons in two and three dimensions. In contrast to the…
Bounded excitons in transition metal dichalcogenides monolayers lead to numerous opto-electronic applications, which require a detailed understanding of the exciton dynamics. The dynamical properties of excitons with finite momentum…
Spatially resolved EELS has been performed at diffuse interfaces between MoS$_2$ and MoSe$_2$ single layers. With a monochromated electron source (20 meV) we have successfully probed excitons near the interface by obtaining the low loss…
We present a computational approach for exciton calculations in two-dimensional (2D) materials within the Bethe-Salpeter equation (BSE) framework, employing an atomistic description with point-like orbitals. Unlike widespread efficient…
Using first principles many-body theory methods (GW+BSE) we demonstrate that optical properties of graphane are dominated by localized charge-transfer excitations governed by enhanced electron correlations in a two-dimensional dielectric…
Excitons are electron-hole pairs appearing below the band gap in insulators and semiconductors. They are vital to photovoltaics, but are hard to obtain with time-dependent density-functional theory (TDDFT), since most standard…
We compare first-principle band gaps and optical absorption spectra of single- and double-layer fluorographene with bulk graphite fluoride. The electronic properties are calculated using the many-body GW approximation and the optical…
Various properties of interlayer excitons in double-layer transition metal dichalcogenides quantum dots are analyzed using a low-energy effective Hamiltonian with Coulomb interaction. We solve the single-particle Hamiltonian with and…
The optical response of phosphorene can be gradually changed by application of moderate uniaxial compression, as the material undergoes the transition into an indirect gap semiconductor and eventually into a semimetal. Strain tunes not only…
Exciton condensation in semiconductors and semimetals has long been predicted but remains elusive. In a semiconductor, condensation occurs when the exciton binding energy matches the band gap. This binding energy results from a balance…
With the example of hexagonal boron nitride, we demonstrate how the character of electron-hole (e-h) pairs in van der Waals bound low-dimensional systems is driven by layer stacking. Four types of excitons appear, with either a two- or…
Optical properties of heterostructures composed of layered 2D materials, such as transition metal dichalcogenides (TMDs) and graphene, are broadly explored. Of particular interest are light-induced energy transfer mechanisms in these…
We have developed a theory of exciton-polariton band structure of resonant three-dimensional photonic crystals for arbitrary dielectric contrast and effective mass of the exciton that is excited in one of the compositional materials. The…
One of the main interests of 2D materials is their ability to be assembled with many degrees of freedom for tuning and manipulating excitonic properties. There is a need to understand how the structure of the interfaces between atomic…