@article{HarkinBrochSchrecketal.2016, author = {Harkin, David J. and Broch, Katharina and Schreck, Maximilian and Ceyman, Harald and Stoy, Andreas and Yong, Chaw-Keong and Nikolka, Mark and McCulloch, Ian and Stingelin, Natalie and Lambert, Christoph and Sirringhaus, Henning}, title = {Decoupling charge transport and electroluminescence in a high mobility polymer semiconductor}, series = {Advanced Materials}, volume = {28}, journal = {Advanced Materials}, number = {30}, doi = {10.1002/adma.201600851}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-187670}, pages = {6378-6285}, year = {2016}, abstract = {Fluorescence enhancement of a high-mobility polymer semiconductor is achieved via energy transfer to a higher fluorescence quantum yield squaraine dye molecule on 50 ps timescales. In organic light-emitting diodes, an order of magnitude enhancement of the external quantum efficiency is observed without reduction in the charge-carrier mobility resulting in radiances of up to 5 W str\(^{-1}\) m\(^{-2}\) at 800 nm.}, language = {en} } @article{PloetzPolyutovIvanovetal.2016, author = {Pl{\"o}tz, P.-A. and Polyutov, S. P. and Ivanov, S. D. and Fennel, F. and Wolter, S. and Niehaus, T. and Xie, Z. and Lochbrunner, S. and W{\"u}rthner, Frank and K{\"u}hn, O.}, title = {Biphasic aggregation of a perylene bisimide dye identified by exciton-vibrational spectra}, series = {Physical Chemistry Chemical Physics}, volume = {18}, journal = {Physical Chemistry Chemical Physics}, number = {36}, doi = {10.1039/c6cp04898f}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-187387}, pages = {25110-25119}, year = {2016}, abstract = {The quantum efficiency of light emission is a crucial parameter of supramolecular aggregates that can be tuned by the molecular design of the monomeric species. Here, we report on a strong variation of the fluorescence quantum yield due to different phases of aggregation for the case of a perylene bisimide dye. In particular, a change of the dominant aggregation character from H- to J-type within the first aggregation steps is found, explaining the observed dramatic change in quantum yield. This behaviour is rationalised by means of a systematic study of the intermolecular potential energy surfaces using the time-dependent density functional based tight-binding (TD-DFTB) method. This provides a correlation between structural changes and a coupling strength and supports the notion of H- type stacked dimers and J-type stack-slipped dimers. The exciton-vibrational level structure is modelled by means of an excitonic dimer model including two effective vibrational modes per monomer. Calculated absorption and fluorescence spectra are found to be in reasonable agreement with experimental ones, thus supporting the conclusion on the aggregation behaviour.}, language = {en} } @phdthesis{Dobrawa2004, author = {Dobrawa, Rainer Anton}, title = {Synthesis and characterization of terpyridine-based fluorescent coordination polymers}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-10367}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2004}, abstract = {Complexation properties of 2,2':6',2''-terpyridine (tpy) have been studied with a series of first row transition metal ions by UV-vis, 1H NMR and isothermal titration calorimetry and ƒ´H values for the tpy complexation processes have been determined. These studies reveal that Zn2+ is the best suited metal ion for the reversible coordination of the terpyridine ligand. Thus, supramolecular coordination polymerization of perylene bisimide fluorophores containing terpyridine functionalities have been investigated by using Zn2+ as metal ion. The formation of the dimeric complexes in the case of monotopic model comounds and coordination polymerization of ditopic functional building blocks have been confirmed by 1H NMR studies. The optical properties of dimeric and polymeric complexes have been investigated by UV-vis and fluorescence spectroscopy. The Zn2+ coordination to the terpyridine unit does not effect the advantageous fluorescence properties of perylene bisimide moieties. The reversibility of the formation of coordination polymers has been established by 1H NMR and additionally by DOSY NMR and fluorescence anisotropy measurements. Coordination polymer strands can be visualized by atomic force microscopy (AFM), which also reveals the formation of an ordered monolayer film at higher concentration. The average polymer length has been determined by AFM to 15 repeat units, which correlates well with the value estimated by 1H NMR to >10 repeat units.}, subject = {Terpyridinderivate <2}, language = {en} }