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HL: Halbleiterphysik
HL 14: Poster I
HL 14.59: Poster
Montag, 24. März 2003, 17:00–19:30, HSZ/P2
Microscopic assignments of time-resolved photoluminescence in α-PTCDA single crystals — •Reinhard Scholz1, Andrei Yu. Kobitski1,2, Igor Vragović1, Thorsten U. Kampen1, Hans-Peter Wagner3, and Dietrich R. T. Zahn1 — 1Institut für Physik, Technische Universität Chemnitz — 2Abteilung Biophysik, Univeristät Ulm — 3Department of Physics, University of Cincinnati, USA
In the present work, we analyse the radiative and non-radiative recombination channels in α-PTCDA (3,4,9,10 perylene tetracarboxylic dianhydride) by applying time-resolved photoluminescence (PL) techniques in the 100 ns range between temperatures of T=11 K and T=300 K [1,2]. These experimental findings are interpreted with microscopic calculations of the dispersion of Frenkel excitons [3] and the investigation of different dimer geometries using time-dependent density functional theory [2]. Based on the latter approach, we can identify radiative recombination from excimer states and from anion-cation pairs. From the temperature dependence of the different PL channels we gain some insight into radiative lifetimes and the energy barriers for non-radiative de-excitation.
[1] A. Yu. Kobitiski, R. Scholz, I. Vragović, H.P. Wagner, and D. R. T. Zahn, Phys. Rev. B 66, 153204 (2002).
[2] R. Scholz, A. Yu. Kobitski, I. Vragović, T. U. Kampen, D. R. T. Zahn, and H.-P. Wagner, Proc. 26th Int. Conf. Phys. Semicond. (2002).
[3] R. Scholz, I. Vragović, A. Yu. Kobitski, M. Schreiber, H. P. Wagner, and D. R. T. Zahn, phys. stat. sol (b) 234, 402 (2002).