相关论文: Indirect Optical Absorption of Single Crystalline …

A comprehensive ellipsometric study was performed on Fe$_{1-x}$Co$_{x}$Si single crystals in the spectral range from 0.01 eV to 6.2 eV. Direct and indirect band gaps of 73 meV and 10 meV, respectively, were observed in FeSi at 7 K. One of…

A new interpretation of the optical and energy-loss spectra of hexagonal boron nitride is provided based on first-principle calculations. We show that both spectra cannot be explained by independent-particle transitions but are strongly…

Theoretical and numerical calculations of the optical absorption spectra of excitons interacting with longitudinal-optical phonons in quasi-2D polar semiconductors are presented. In II-VI semiconductor quantum wells, exciton binding energy…

From an investigation of the optical conductivity of FeSi single crystals using FTIR spectroscopy in the frequency range from 30 to 20000 wavenumbers we conclude that the transverse effective charge of the Fe and Si ions is approximately…

In this paper, we simulate the linear absorption spectra of the MePTCDI and PTCDA crystals. The basic Hamiltonian describes the Frenkel excitons and charge-transfer excitons mixing in the molecular stack (point group C_i) and their linear…

The optical absorption spectrum of the carbon (4,2) nanotube is computed using an ab-initio many-body approach which takes into account excitonic effects. We develop a new method involving a local basis set which is symmetric with respect…

The phonon-assisted interband optical absorption spectrum of silicon is calculated at the quasiparticle level entirely from first principles. We make use of the Wannier interpolation formalism to determine the quasiparticle energies, as…

A first-principles study on the quasiparticles energy and optical absorption spectrum of fluorographene is presented by employing the GW + Bethe-Salpeter Equation (BSE) method with many-electron effects included. The calculated band gap is…

We calculate the binding energy, transition energies, oscillator strength, and absorption coefficient of indirect excitons in transition metal dichalcogenide (TMDC) double layers separated by an integer number of hexagonal boron nitride…

We investigate high resolution laser absorption spectroscopy of a single InGaAs/GaAs self-assembled quantum dot embedded in a field-effect structure. We show experimentally that the interband optical absorption to the lower Zeeman branch of…

We measured the reflectivity of a single crystal of FeSi from the far-infrared to the visible region (50-20000 wavenumber), varying the temperature between 4 and 300 K. The optical conductivity function was obtained via Kramers-Kronig…

We investigate phase-dependent electronic and excitonic phenomena in monolayer Y2TeO2 MOenes in the 1T and 2H polymorphs using first-principles theory and an effective many-body framework. Phonon spectra and elastic stability criteria…

We use maximum entropy techniques to extract an electron-phonon density from optical data in the normal state at T = 45 K in MgB2. Limiting the analysis to a range of phonon energies below 110 meV which is sufficient to capture all phonon…

We find that the optical properties of carbon nanotubes reflect remarkably strong effects of exciton-phonon coupling. Tight-binding calculations show that a significant fraction of the spectral weight of the absorption peak is transferred…

We investigated excitonic absorptions in GaAs/AlAs/GaAs single barrier heterostructure using both photocapacitance and photocurrent spectroscopies at room temperature. Photocapacitance spectra show well defined resonance peak of indirect…

The optical properties of silicon can be greatly tuned by applying strain and opening new perspectives, particularly in applications where infrared is key. In this work, we use a recent model for the indirect light absorption of silicon and…

The effects of the electron-phonon interaction on optical excitations can be understood in terms of exciton-phonon coupling, and require a careful treatment in low-dimensional materials with strongly bound excitons or strong electron-hole…

Monoclinic bismuth vanadate (m-BiVO$_4$) is a promising indirect band gap semiconductor for photoelectrochemical water splitting, yet the characteristics of its low-lying photoexcitations, or excitons, remain poorly understood. Here, we use…

We present an \textit{ab initio} method to calculate phonon-assisted absorption and emission spectra in the presence of strong excitonic effects. We apply the method to bulk hexagonal BN which has an indirect band gap and is known for its…

Silicon carbide (SiC) is an indirect-gap semiconductor material widely used in electronic and optoelectronic applications. While experimental measurements of the phonon-assisted absorption coefficient of SiC across its indirect gap have…