AVS 61st International Symposium & Exhibition
    Electronic Materials and Processing Tuesday Sessions
       Session EM-TuP

Paper EM-TuP12
Electronic and Vibrational Structures in Photoemission Spectra for Dibenzopentacene on Au(111)

Tuesday, November 11, 2014, 6:30 pm, Room Hall D

Session: Electronic Materials and Processing Poster Session
Presenter: Masaru Aoki, The University of Tokyo, Japan
Authors: M. Aoki, The University of Tokyo, Japan
A. Suzuki, The University of Tokyo, Japan
H. Sato, The University of Tokyo, Japan
K. Shudo, Yokohama National University, Japan
S. Masuda, The University of Tokyo, Japan
Correspondent: Click to Email

Electronic properties of dibenzopentacene (DBP) thin films on Au(111) were examined by ultraviolet photoemission spectroscopy (UPS), metastable atom electron spectroscopy (MAES),1,2 and first-principles DFT calculation. The UPS and MAES spectra for DBP multilayer show four bands near the Fermi level (EF) due to π-derived 8bg(HOMO), 7bg+7au, 6au, and 6bg states, in agreement with an earlier study.3 The corresponding bands emerge in the monolayer region, but the bandwidth of the HOMO band is much narrower than that in the multilayer. Furthermore, the HOMO band consists of three peaks with interval of ~160 meV, which is attributed to the vibrational structure of the CC stretching modes of DBP+ ion produced by photoionization. A similar vibronic coupling has been reported for organic molecules on inert surfaces such as phthalocyanine on graphite4 and pentacene on graphite,5 but to our knowledge there is no report in the organic–metal system. In the conference, we will introduce the weak interactions between DBP and Au(111) based on our DFT calculation, temperature-dependent (50-273 K) vibronic structure, and lifetime of photohole in organic–metal system.

References

[1] Y. Harada, S. Masuda, H. Ozaki, Chem. Rev. 97, 1897 (1997).

[2] S. Masuda, Appl. Surf. Sci. 256, 4054 (2010).

[3] B. Mahns, F. Roth, A. König, M. Grobosch, M. Knupfer, T. Hahn, Phys. Rev. B 86, 035209 (2012).

[4] S. Kera, H. Yamane, I. Sakuragi, K. K. Okudaira, N. Ueno, Chem. Phys. Lett. 364, 93 (2002).

[5] H. Yamane, S. Nagamatsu, H. Fukagawa, S. Kera, R. Friedlein, K. K. Okudaira, N. Ueno, Phys. Rev. B 72, 153412 (2005).