We study the dark excitons at interface of sharp lateral heterostructure two-dimensional transition metal dichalcogenides. By introducing a low-energy effective Hamiltonian model, we find energy dispersion relation exciton and show how it depends on onsite composed materials their spin-orbit coupling strengths. It is shown that effect geometrical structure interface, as deformation gauge field ...

We present a study of the electronic and optical properties of a series of alkali halide crystals AX, with A = Li, Na, K, Rb and X = F, Cl, Br based on a recent implementation of hybrid-exchange time-dependent density functional theory (TD-DFT) (TD-B3LYP) in the all-electron Gaussian basis set code CRYSTAL. We examine, in particular, the impact of basis set size and quality on the prediction of...

The demonstration of degeneracy of the exciton spin states is an important step towards the production of entangled photons pairs from the biexciton cascade. We measure the fine structure of exciton and biexciton states for a large number of single InAs quantum dots in a GaAs matrix; the energetic splitting of the horizontally and vertically polarised components of the exciton doublet is shown ...

Photoluminescence of polycrystalline hexagonal boron nitride (hBN) was measured by means of time-and energy-resolved spectroscopy methods. The observed bands are related to DAP transitions, impurities and structural defects. The excitation of samples by high-energy photons above 5.4 eV enables a phenomenon of photostimulated luminescence (PSL), which is due to distantly trapped CB electrons and...

We investigate the electron-phonon coupling in CH3NH3PbX3 lead halide perovskites through observation of Landau levels and high-order excitons at weak magnetic fields, where cyclotron energy is significantly smaller than longitudinal optical phonon energy. The reduced masses carriers exciton binding energies obtained from these data are clearly influenced by polaron formation. analyze field-dep...

A phenomenological coupled exciton model is proposed in order to characterize optical excitations in extended dendrimers. An onsite exciton state is assigned at each phenyl rings and a nearest neighbor hopping integral which obeys the Gaussian distribution is considered between the exciton states. The decreasing optical excitation energy with respect to the dendrimer size indicates the presence...

Numerical simulations of exciton migration along a one-dimensional lattice via Forster energy transfer are reported. The roles of static Gaussian energetic disorder and transition dipole orientational disorder are investigated. Both disorder mechanisms result in subdiffusive behavior during the initial phase of energy migration, tending asymptotically to normal diffusion. The dependence of the ...

Exciton binding energy and lifetime are the two most important parameters controlling exciton dynamics, general consensus is that larger former, latter. However, our first-principles study of monolayer ferroelectric ${\mathrm{TiOCl}}_{2}$ shows this not always case. We find polarization tends to weaken but enhance lifetime. This stems from different effects induced built-in electric field struc...