Hybrid cluster-expansion and density-functional-theory approach for optical absorption in TiO2

Autor:	Vänskä, O., Ljungberg, M., Springer, P., Sánchez-Portal, D., Kira, M., Koch, S. W.
Rok vydání:	2015
Předmět:	Condensed Matter - Materials Science
Druh dokumentu:	Working Paper
DOI:	10.1364/JOSAB.33.00C123
Popis:	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. Comment: 14 pages, 4 figures
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1512.05156 Zobrazit plný text záznamu View this record from Arxiv