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Ultra-sensitive pressure dependence of bandgap of rutile-GeO2 revealed by many body perturbation theory

Samanta, Atanu and Jain, Manish and Singh, Abhishek K (2015) Ultra-sensitive pressure dependence of bandgap of rutile-GeO2 revealed by many body perturbation theory. In: JOURNAL OF CHEMICAL PHYSICS, 143 (6).

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Official URL: http://dx.doi.org/10.1063/1.4928526

Abstract

The reported values of bandgap of rutile GeO2 calculated by the standard density functional theory within local-density approximation (LDA)/generalized gradient approximation (GGA) show a wide variation (similar to 2 eV), whose origin remains unresolved. Here, we investigate the reasons for this variation by studying the electronic structure of rutile-GeO2 using many-body perturbation theory within the GW framework. The bandgap as well as valence bandwidth at Gamma-point of rutile phase shows a strong dependence on volume change, which is independent of bandgap underestimation problem of LDA/GGA. This strong dependence originates from a change in hybridization among O-p and Ge-(s and p) orbitals. Furthermore, the parabolic nature of first conduction band along X-Gamma-M direction changes towards a linear dispersion with volume expansion. (C) 2015 AIP Publishing LLC.

Item Type: Journal Article
Additional Information: Copy right for this article belongs to the AMER INST PHYSICS, 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA
Department/Centre: Division of Chemical Sciences > Materials Research Centre
Division of Physical & Mathematical Sciences > Physics
Depositing User: Id for Latest eprints
Date Deposited: 24 Sep 2015 05:20
Last Modified: 24 Sep 2015 05:20
URI: http://eprints.iisc.ac.in/id/eprint/52399

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