Münster 1999 – scientific programme
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HL: Halbleiterphysik
HL 12: Poster I
HL 12.14: Poster
Monday, March 22, 1999, 14:00–18:00, Z
Total Current Spectroscopy study of PTCDA films — •A. Morozov1, T.U. Kampen2, and D.R.T. Zahn2 — 1Research Institute for Physics, St. Petersburg University, Russia — 2Institut f"ur Physik, Technische Universit"at, D-09107 Chemnitz
Total Current Spectroscopy was used for the investigation of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) films grown on hydrogen passivated Si(111). The primary electron energy was varied in a range from 0 to 20 eV. During measurements a typical current density of 5· 10−9 A/cm2 was used. The total current spectrum of a PTCDA film is characterized by intensive fine structure in the energy range 0 - 15 eV above the vacuum level. These structures can be associated with empty electronic states located above the vacuum level. Spectra at different film thicknesses are compared in order to evaluate the interaction between the PTCDA molecules and the substrate. Following the primary peak position during film deposition, one can trace the work function variation as a function of layer thickness.