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).

PDF Jou_of_Che_Phy_143-6_064703_2015.pdf - Published Version Restricted to Registered users only Download (1MB) | Request a copy

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
Publication:	JOURNAL OF CHEMICAL PHYSICS
Publisher:	AMER INST PHYSICS
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
Date Deposited:	24 Sep 2015 05:20
Last Modified:	24 Sep 2015 05:20
URI:	http://eprints.iisc.ac.in/id/eprint/52399

Actions (login required)

View Item