The optical selection rules of a graphene quantum dot in external electric fields. Issue 37 (26th April 2017)

• Record Type: Journal Article
• Authors: Dong, Qing-Rui; Liu, Chun-Xiang
• Is Part Of: RSC advances. Volume 7:Issue 37(2017)
• Page Start: 22771
• Page End: 22776
• Publication Date: 2017-04-26
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c7ra03747c
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : We study theoretically the triangular zigzag graphene quantum dot in electric fields and find that there exist the remarkable optical selection rules in the FIR spectra. Abstract : We study theoretically the single-electron triangular zigzag graphene quantum dot in three typical in-plane electric fields. The far-infrared absorption spectra of the dot are calculated by the tight-binding method and then the optical selection rules are identified by contrast with the corresponding energy spectra. Our result shows that there exist the remarkable optical selection rules due to the C 3 symmetry of the dot. When the electric field possesses also the C 3 symmetry, there are only two absorption peaks in the absorption spectra. As the C 3 symmetry of the system is damaged by the electric fields, both the intensity of the strongest peak and the number of the forbidden transitions decrease gradually. Moreover, the polarization causes the decrease of the peak intensities and even new forbidden transitions. Our findings may be useful for the application of graphene quantum dots to electronic and optoelectronic devices.