Universität zu Köln

Alavi, Seyed Khalil, Senkovskiy, Boris, V, Pfeiffer, Markus, Haberer, Danny, Fischer, Felix R., Grueneis, Alexander and Lindfors, Klas ORCID: 0000-0002-6482-5605 (2019). Probing the origin of photoluminescence brightening in graphene nanoribbons. 2D Mater., 6 (3). BRISTOL: IOP PUBLISHING LTD. ISSN 2053-1583

Full text not available from this repository.

Abstract

We measure the absolute absorbance of a single layer of seven atom wide armchair graphene nanoribbons and study the influence of laser-induced defects on the absorption spectrum of the ribbons. We find that the absorption spectrum shows a broad peak at approximately 2.4 eV that is attributed to excitonic transitions and a smaller peak at 1.77 eV. The low-energy peak is diminished when we induce defects in the material. Simultaneously the photoluminescence is significantly enhanced. We thus attribute the 1.77 eV spectral feature in the absorption spectrum to a quenching state, which energetically coincides with the emission. Our results clearly demonstrate the significance of this state in photoluminescence processes in the ribbons. We additionally measure the dependence of the generation of defects on the energy of the incident photons and the photoluminescence excitation spectrum. The photoluminescence excitation efficiency peaks at a higher photon energy than the maximum absorption, hinting at an efficient decay from higher energetic states to the emissive state.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Alavi, Seyed Khalil UNSPECIFIED UNSPECIFIED UNSPECIFIED Senkovskiy, Boris, V UNSPECIFIED UNSPECIFIED UNSPECIFIED Pfeiffer, Markus UNSPECIFIED UNSPECIFIED UNSPECIFIED Haberer, Danny UNSPECIFIED UNSPECIFIED UNSPECIFIED Fischer, Felix R. UNSPECIFIED UNSPECIFIED UNSPECIFIED Grueneis, Alexander UNSPECIFIED UNSPECIFIED UNSPECIFIED Lindfors, Klas UNSPECIFIED orcid.org/0000-0002-6482-5605 UNSPECIFIED
URN:	urn:nbn:de:hbz:38-137314
DOI:	10.1088/2053-1583/ab1116
Journal or Publication Title:	2D Mater.
Volume:	6
Number:	3
Date:	2019
Publisher:	IOP PUBLISHING LTD
Place of Publication:	BRISTOL
ISSN:	2053-1583
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	Faculty of Mathematics and Natural Sciences > Department of Chemistry > Institute of Physical Chemistry
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language ON-SURFACE SYNTHESIS; CARBON NANOTUBES Multiple languages Materials Science, Multidisciplinary Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/13731