Structural and electronic properties of fluorographene

Abstract

The structural and electronic characteristics of fluorinated graphene are investigated based on first-principles density-functional calculations. A detailed analysis of the energy order for stoichiometric fluorographene membranes indicates that there exists prominent chair and stirrup conformations, which correlate with the experimentally observed in-plane lattice expansion contrary to a contraction in graphane. The optical response of fluorographene is investigated using the GW-Bethe-Salpeter equation approach. The results are in good conformity with the experimentally observed optical gap and reveal predominant charge-transfer excitations arising from strong electron-hole interactions. The appearance of bounded excitons in the ultraviolet region can result in an excitonic Bose-Einstein condensate in fluorographene. Chair and stirrup conformers of fluoro-graphene are prominent stoichiometric membranes, which correlate with the experimentally observed in-plane lattice expansion. The calculated optical response of fluorographene reveals predominant charge-transfer excitations. The bounded excitons in the ultraviolet region can result in an excitonic Bose-Einstein condensate in fluorographene. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.