Comparison of organic and inorganic layers for structural templating of pentacene thin films
File(s)
Author(s)
Kim, Dong Kuk
Lubert-Perquel, Daphne
Heutz, Sandrine
Type
Journal Article
Abstract
Pentacene is a key organic semiconductor, which has achieved prominence in transistor applications and as an archetypal material for singlet fission, the process whereby the absorption of one photon leads to the formation of two triplet states. Functional properties of molecules are highly anisotropic, and control over the molecular orientation in thin films with structural templating is commonly implemented as a route for governing the morphology and structure of organic films. Among the structural templating layers, 3, 4, 9, 10 perylenetetracarboxylic dianhydride (PTCDA) and copper (I) iodide (CuI) have been shown to effectively template aromatic systems such as phthalocyanines. Here, we extend their use to pentacene thin films and find that a successful transition to a flat-lying arrangement is achieved with CuI films grown at high temperatures, but not with PTCDA. As a result, we postulate a model based on quadrupole interactions as the driving force behind the molecular orientation of pentacene. A 0.25 eV increase in work function and a two-fold increase in absorption are recorded for the induced flat-lying orientation. Therefore, our templating methodology provides design opportunities for optoelectronic devices that require a predominantly flat-lying orientation.
Date Issued
2020-01-01
Date Acceptance
2019-07-22
Citation
Materials Horizons, 2020, 7 (1), pp.289-298
ISSN
2051-6355
Publisher
Royal Society of Chemistry
Start Page
289
End Page
298
Journal / Book Title
Materials Horizons
Volume
7
Issue
1
Copyright Statement
© The Royal Society of Chemistry 2019
Sponsor
Engineering and Physical Sciences Research Council
Grant Number
EP/L015277/1
Publication Status
Published
Date Publish Online
2019-07-30