• DOI:10.1103/PhysRevB.100.075135
• Corpus ID: 119221922

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

@article{Chen2019AbI,
  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},
  year={2019}
}

• Hsiao-Yi Chen, V. Jhalani, +1 author M. Bernardi
• Published 25 January 2019
• Physics
• 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 from bulk crystals to nanostructures and molecules. We derive the rate of exciton radiative recombination in bulk crystals, isolated systems, and in one- and two-dimensional materials, using Fermi's golden rule within the Bethe-Salpeter equation approach. We present benchmark calculations of radiative lifetimes in a GaAs crystal and in gas-phase organic molecules, obtaining results in agreement with experiment. Our work provides a general method for studying exciton recombination and light emission in bulk, nanostructured and molecular materials from first principles.