Electronic structure and optical properties of F centers in alpha-alumina

Biswas, Tathagata and Jain, Manish (2019) Electronic structure and optical properties of F centers in alpha-alumina. In: PHYSICAL REVIEW B, 99 (14).

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Abstract

We use a state-of-the-art GW Bethe-Salpeter equation (BSE) formalism to study electronic structure and optical properties of oxygen vacancies (F centers) in alpha-alumina. The density functional theory (DFT) + GW formalism has been employed to compute the charge transition levels (CTLs) for oxygen vacancies. We propose a reformulation of the DFT+GW approach to calculate these CTLs. Our new approach allows for transparent application of electrostatic corrections required in finite supercell calculations using periodic boundary conditions. We find that F centers in this material introduce deep donor levels, (+2/+1) at 2.4 eV, and a (+1/0) level at 3.9 eV above the valence band maximum. We also study F-center absorption and emission processes using constrained DFT and BSE. Our calculated absorption and emission energies are in excellent agreement with experiments and provide an unambiguous interpretation of the same.

Item Type:	Journal Article
Publication:	PHYSICAL REVIEW B
Publisher:	AMER PHYSICAL SOC
Additional Information:	Copyright of this article belongs to AMER PHYSICAL SOC
Keywords:	PLASTIC-DEFORMATION; QUASI-PARTICLE; AL2O3; DEFECTS
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	21 May 2019 11:47
Last Modified:	21 May 2019 11:47
URI:	http://eprints.iisc.ac.in/id/eprint/62601

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