Quantitatively identical orientation-dependent ionization energy and electron affinity of diindenoperylene

[ABSTRACT] Molecular orientation dependences of the ionization energy (IE) and the electron affinity (EA) of diindenoperylene (DIP) films were studied by using ultraviolet photoemission spectroscopy and inverse photoemission spectroscopy. The molecular orientation was controlled by preparing the DIP films on graphite and SiO2 substrates. The threshold IE and EA of DIP thin films were determined to be 5.81 and 3.53 eV for the film of flat-lying DIP orientation, respectively, and 5.38 and 3.13 eV for the film of standing DIP orientation, respectively. The result indicates that the IE and EA for the flat-lying film are larger by 0.4 eV and the frontier orbital states shift away from the vacuum level compared to the standing film. This rigid energy shift is ascribed to a surface-electrostatic potential produced by the intramolecular polar bond (>C- -H+) for standing orientation and p-electron tailing to vacuum for flat-lying orientation.

https://opac.ll.chiba-u.jp/da/curator/105791/

https://opac.ll.chiba-u.jp/da/curator/105791/appl_phys_lett_103-253301.pdf

AIP Publishing

学術雑誌論文

Applied Physics Letters

103

253301

2013-12-16

10.1063/1.4850531

publisher

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Applied Physics Letters 103, 253301 (2013) and may be found at https://aip.scitation.org/doi/10.1063/1.4850531.