Lower hole-injection barrier between pentacene and a 1-hexadecanethiol-modified gold substrate with a lowered work function
SCIE
SCOPUS
- Title
- Lower hole-injection barrier between pentacene and a 1-hexadecanethiol-modified gold substrate with a lowered work function
- Authors
- Hong, K; Lee, JW; Yang, SY; Shin, K; Jeon, H; Kim, SH; Yang, C; Park, CE
- Date Issued
- 2008-02
- Publisher
- ELSEVIER SCIENCE BV
- Abstract
- We used ultraviolet photoemission spectroscopy (UPS) to study the hole injection barrier at the interface between pentacene and a gold surface treated with 1-hexadecanethiol (HDT). Through these UPS in-situ experiments, we found that the energy barrier between HDT-modified gold and pentacene was 0.74 eV. This energy barrier was 0. 11 eV smaller than that between bare gold and pentacene, despite the work function of HDT-modified gold being 1.08 eV lower than that of bare gold. This result does not follow the typical trend, whereby decreasing the work function of a metal increases the energy barrier. The observed behavior can be explained by two factors. First, the bare gold substrate exhibited a large interface dipole, whereas the HDT-modified gold did not. And second, pentacene on the HDT-modified gold substrate had a lower ionization energy than pentacene on bare gold. This finding can be explained in terms of the polarization energy related to the more crystalline structure of pentacene on the HDT-modified gold substrate, which was established by X-ray diffraction analysis. For comparison, we also measured the injection barrier between the amorphous organic semiconductor, N,N'-diphenyl-N,N'bis(1-naphthyl-1,1'-biphenyl-4,4'-diamine (alpha-NPD)), and HDT-modified gold. (c) 2007 Elsevier B.V. All rights reserved.
- Keywords
- hole-injection barrier; pentacene; crystalline; gold; 1-hexadecanethiol; self-assembled monolayer; SELF-ASSEMBLED MONOLAYERS; ORGANIC ELECTRONIC DEVICES; ENERGY-LEVEL ALIGNMENT; CHARGE NEUTRALITY LEVEL; THIN-FILM TRANSISTORS; PHOTOELECTRON-SPECTROSCOPY; DIPOLE FORMATION; INTERFACES; METAL; PHOTOEMISSION
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/22949
- DOI
- 10.1016/j.orgel.2007.07.006
- ISSN
- 1566-1199
- Article Type
- Article
- Citation
- ORGANIC ELECTRONICS, vol. 9, no. 1, page. 21 - 29, 2008-02
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