Dresden 2014 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 109: Ultra-fast phenomena I
HL 109.2: Vortrag
Freitag, 4. April 2014, 09:45–10:00, POT 006
Ultrafast charge carrier and exciton dynamics at the SP6/ZnO(10-10) interface — •Laura Foglia1, Mino Kris Sparenberg2, Fritz Henneberger2, Julia Stähler1, and Martin Wolf1 — 1Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Deutschland — 2Institut für Physik, Humboldt-Universität zu Berlin, Berlin, Germany
The efficiency of hybrid organic inorganic devices depends strongly on the timescale of competing electronic processes, such as interfacial charge transfer and bulk exciton decay. These typically ultrafast timescales can be accessed by pump-probe techniques, where a pump laser pulse initially excites the system and the change of electronic or optical properties is probed by a second laser pulse, as a function of time delay. We apply broadband transient transmission spectroscopy to investigate the carrier dynamics at the interface between ZnO and a spirobifluorene derivative, SP6. The system is first excited at 3.6 eV (across the SP6 HOMO-LUMO and ZnO band gap) and subsequently the transmission in the visible range (1.7-2.9 eV) is monitored. In this manner the excited state absorption is probed by changes in the polarization due to the evolution of the electronic population in both the SP6 LUMO and ZnO conduction band. First results show sub-picosecond dynamics, much shorter than the exciton dynamics previously observed by time-resolved photoluminescence.