Hybrid cluster-expansion and density-functional-theory approach for optical absorption in TiO2
Materials Science
2016-06-29 v1
Abstract
A combined approach of first-principles density-functional calculations and the systematic cluster-expansion scheme is presented. The dipole, quadrupole, and Coulomb matrix elements obtained from ab initio calculations are used as an input to the microscopic many-body theory of the excitonic optical response. To demonstrate the hybrid approach for a nontrivial semiconductor system, the near-bandgap excitonic optical absorption of rutile TiO2 is computed. Comparison with experiments yields strong evidence that the observed near-bandgap features are due to a dipole-forbidden but quadrupole-allowed 1s-exciton state.
Keywords
Cite
@article{arxiv.1512.05156,
title = {Hybrid cluster-expansion and density-functional-theory approach for optical absorption in TiO2},
author = {O. Vänskä and M. Ljungberg and P. Springer and D. Sánchez-Portal and M. Kira and S. W. Koch},
journal= {arXiv preprint arXiv:1512.05156},
year = {2016}
}
Comments
14 pages, 4 figures