Pentacene Excitons In Strong Electric Fields
Keywords
density functional calculations; electroluminescence; excitons; pentacene; scanning probe microscopy
Abstract
Electroluminescence spectroscopy of organic semiconductors in the junction of a scanning tunneling microscope (STM) provides access to the polarizability of neutral excited states in a well-characterized molecular geometry. We study the Stark shift of the self-trapped lowest singlet exciton at 1.6 eV in a pentacene nanocrystal. Combination of density functional theory (DFT) and time-dependent DFT (TDDFT) with experiment allows for assignment of the observation to a charge-transfer (CT) exciton. Its charge separation is perpendicular to the applied field, as the measured polarizability is moderate and the electric field in the STM junction is strong enough to dissociate a CT exciton polarized parallel to the applied field. The calculated electric-field-induced anisotropy of the exciton potential energy surface will also be of relevance to photovoltaic applications.
Publication Date
2-5-2018
Publication Title
ChemPhysChem
Volume
19
Issue
3
Number of Pages
277-283
Document Type
Article
Personal Identifier
scopus
DOI Link
https://doi.org/10.1002/cphc.201701174
Copyright Status
Unknown
Socpus ID
85040695181 (Scopus)
Source API URL
https://api.elsevier.com/content/abstract/scopus_id/85040695181
STARS Citation
Kuhnke, Klaus; Turkowski, Volodymyr; Kabakchiev, Alexander; Lutz, Theresa; and Rahman, Talat S., "Pentacene Excitons In Strong Electric Fields" (2018). Scopus Export 2015-2019. 9291.
https://stars.library.ucf.edu/scopus2015/9291