Regensburg 2000 – scientific programme
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HL: Halbleiterphysik
HL 38: Poster III: Transporteigenschaften (1-14), Optische Eigenschaften (15-31), Grenz-/Oberfl
ächen (32-44), Heterostrukturen (45-57), Bauelemente (58-67), Gitterdynamik (68-69), Diamant (70), Raster-Tunnel-Mikroskopie (71)
HL 38.22: Poster
Thursday, March 30, 2000, 14:00–19:00, B
Raman spectroscopy of PTCDA single crystals — •D. A. Tenne1, S. Park2, T. U. Kampen2, R. Scholz2, and D. R. T. Zahn2 — 1Institute of Semiconductor Physics, 630090 Novosibirsk, Russia — 2Institut für Physik, Technische Universität Chemnitz, D-09107 Chemnitz, Germany
Single crystals of organic semiconductor the 3,4,9,10- perylene tetracarboxylic dianhydride (PTCDA) were studied by Raman spectroscopy. The correlation field (Davydov) splitting of internal molecular vibrations due to the interaction of two molecules in a unit cell was observed. We also report the experimental observation of intermolecular vibrations (phonons) of a PTCDA crystal in the low-frequency region of Raman spectra. An approximation based on the phonon frequencies of perylene taking into account larger molecular mass of PTCDA yields reasonable agreement with experiment. Data obtained for vibrational spectra of single crystals were used for the Raman characterization of the structural quality of PTCDA films grown by organic molecular beam deposition on passivated GaAs(100) surfaces. The crystalline structure of these films is evidenced by the observation of Davydov splitting of internal vibrational modes and phonon features of a PTCDA crystal.