Ab initio calculations of exciton radiative lifetimes in bulk crystals, nanostructures, and molecules

  title={Ab initio
 calculations of exciton radiative lifetimes in bulk crystals, nanostructures, and molecules},
  author={Hsiao-Yi Chen and Vatsal A. Jhalani and Maurizia Palummo and Marco Bernardi},
  journal={Physical Review B},
Excitons are bound electron-hole pairs that dominate the optical response of semiconductors and insulators, especially in materials where the Coulomb interaction is weakly screened. Light absorption (including excitonic effects) has been studied extensively using first-principles calculations, but methods for computing radiative recombination and light emission are still in their infancy. Here we show a unified ab initio approach to compute exciton radiative recombination in materials ranging… 

Figures and Tables from this paper

Optical emission from light-like and particle-like excitons in monolayer transition metal dichalcogenides

Several monolayer transition metal dichalcogenides (TMDs) are direct band gap semiconductors and potentially efficient emitters in light emitting devices. Photons are emitted when strongly bound

First-Principles Exciton Radiative Lifetimes in Wurtzite GaN

Gallium nitride (GaN) is a key semiconductor for solid-state lighting, but its radiative processes are not fully understood. Here we show a first-principles approach to accurately compute the

Precise radiative lifetimes in bulk crystals from first principles: the case of wurtzite gallium nitride

A first-principles approach to accurately compute the radiative lifetimes in bulk uniaxial crystals, focusing on wurtzite GaN, shows that taking into account excitons and spin-orbit coupling to include the exciton fine structure is essential for computing accurate radiativelifetimes.

Electron–phonon scattering and excitonic effects in T-carbon

Through first-principles calculations combining many-body perturbation theory, we investigate electron–phonon scattering and optical properties including the excitonic effects of T-carbon. Our

Ab initio modeling of phonon-assisted relaxation of electrons and excitons in semiconductor nanocrystals for multiexciton generation

Electron-phonon and exciton-phonon interactions in nanoclusters are formulated and computed under the framework of GW-BSE (Bethe-Salpeter equation) approach. The phonon effect is modeled with the

Radiative properties of quantum emitters in boron nitride from excited state calculations and Bayesian analysis

Point defects in hexagonal boron nitride (hBN) have attracted growing attention as bright single-photon emitters. However, understanding of their atomic structure and radiative properties remains

Exciton absorption, band structure, and optical emission in biased bilayer graphene

Biased bilayer graphene (BBG) is a variable band gap semiconductor, with a strongly fielddependent band gap of up to 300 meV, making it of particular interest for graphene-based nanoelectronic and

Signatures of Dimensionality and Symmetry in Exciton Band Structure: Consequences for Exciton Dynamics and Transport

It is revealed that the discontinuities in the band structure lead to ultrafast ballistic transport and suggesting that measured exciton diffusion and dynamics are influenced by the underlying exciton dispersion.



Theory and ab initio calculation of radiative lifetime of excitons in semiconducting carbon nanotubes.

A theoretical analysis and first-principles calculation of the radiative lifetime of excitons in semiconducting carbon nanotubes finds an effective lifetime of the order of 10 ns at room temperature, in good accord with recent experiments.

Exciton radiative lifetimes in two-dimensional transition metal dichalcogenides.

The wide radiative lifetime tunability, together with the ability shown here to predict radiative lifetimes from computations, hold unique potential to manipulate excitons in TMDs and their heterostructures for application in optoelectronics and solar energy conversion.

Exciton Band Structure in Two-Dimensional Materials.

It is demonstrated that the exciton band structure, which can be accessed experimentally, instead provides a powerful way to identify the excitons character in low-dimensional materials.

Electron-hole excitations and optical spectra from first principles

We present a recently developed approach to calculate electron-hole excitations and the optical spectra of condensed matter from first principles. The key concept is to describe the excitations of

First-Principles Analysis of Radiative Recombination in Lead-Halide Perovskites

Slow radiative recombination due to a slightly indirect band gap has been proposed to explain the high efficiency of lead-halide perovskite solar cells. Here, we calculate the radiative recombination

Thermodynamics of excitons in semiconductors

During the few microseconds between its laser‐induced creation in a pure semiconductor crystal and its destruction by recombination, a bound electron–hole pair, or exciton, is very active. Like the

Interlayer Coupling and Gate-Tunable Excitons in Transition Metal Dichalcogenide Heterostructures.

This work clarifies the physical picture of interlayer excitons in bilayer vdW heterostructures and predicts a wide range of gate-tunable excited-state properties of 2D optoelectronic devices.

Nonanalyticity, Valley Quantum Phases, and Lightlike Exciton Dispersion in Monolayer Transition Metal Dichalcogenides: Theory and First-Principles Calculations.

The ab initio GW-Bethe-Salpeter equation method is used to calculate the dispersion of excitons in monolayer MoS(2) and find a nonanalytic lightlike dispersion.

Exciton dispersion from first principles

We present a scheme to calculate exciton dispersions in real materials that is based on the first-principles many-body Bethe-Salpeter equation. We assess its high level of accuracy by comparing our