Regensburg 2019 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 38: Organic semiconductors
HL 38.7: Talk
Thursday, April 4, 2019, 11:00–11:15, H33
Electronic excitations in phthalocyanine mixed films — •Lukas Graf1, Louis Doctor1, Nikolay Kovbasa1, Marco Naumann1, Martin Knupfer1, Katrin Ortstein2, and Karl Leo2 — 1IFW Dresden — 2IAPP Dresden
This contribution will present optical and electron spectroscopy experiments on mixed films of phthalocyanines. Phthalocyanines (PC’s) are organic semiconductors which are well suited for fundamental studies as well as applications. Band structure tuning, such as size and position of the bandgap, is common in inorganic semiconductors. In organic semiconductors it was first reported in 2016 for mixtures of ZnPC with fluorinated ZnPC (M. Schwarze et al, Science, 2016). We investigate mixed films of ZnPC and its fluorinated partner F8ZnPC with a particular focus on the electronic excitations. In different ratios they are evaporated in thin films on a KBr substrate. These films are measured by optical spectroscopy (UV,IR, VIS) and with electron energy loss spectroscopy (EELS), a method where the energy-loss of the transmitted electrons through the film can be measured momentum dependently. This unique technique allows us to measure the exciton disperson of the materials and to see how the mixed films’ disperson is just a superposition of the pure molecules or if they are building new properties by being stacked next to each other. This is supported by the DFG (KN393/25, KN293/26).