Organic Thin Film; Nucleation and Growth; Organic Single Crystal; Cyanine Dye; J-aggregate
Gesevičius Donatas, Neels Antonia, Duchêne Léo, Hack Erwin, Heier Jakob, Nüesch Frank (2019), Physical vapour deposition of cyanine salts and their first application in organic electronic devices, in Journal of Materials Chemistry C
, 7(2), 414-423.
Leclaire Nicolas A., Li Musen, Véron Anna C., Neels Antonia, Heier Jakob, Reimers Jeffrey R., Nüesch Frank A. (2018), Cyanine platelet single crystals: growth, crystal structure and optical spectra, in Physical Chemistry Chemical Physics
, 20(46), 29166-29173.
Makha Mohammed, Schwaller Philippe, Strassel Karen, Anantharaman Surendra B., Nüesch Frank, Hany Roland, Heier Jakob (2018), Insights into photovoltaic properties of ternary organic solar cells from phase diagrams, in Science and Technology of Advanced Materials
, 19(1), 669-682.
Wang Lei, Jenatsch Sandra, Ruhstaller Beat, Hinderling Christian, Gesevičius Donatas, Hany Roland, Nüesch Frank (2018), Organic Salt Semiconductor with High Photoconductivity and Long Carrier Lifetime, in Advanced Functional Materials
, 28(16), 1705724-1705724.
Leclaire Nicolas A., Boudoire Florent, Hack Erwin, Bronnimann Rolf, Nuesch Frank A., Heier Jakob (2017), Light Scattering Enhancement at the Absorption Edge in Dewetting Droplets of Cyanine Dyes, in ADVANCED OPTICAL MATERIALS
, 5(5), 1600903.
Organic semiconductors are a promising class of materials for future electro-optical devices. Conjugated polymers and oligomers are leading the field in organic light-emitting devices, organic photovoltaics and thin film transistors. Cyanine dyes are well known in silver halide photography and are successfully applied in DVD technology or as fluorescent probes in biology but have rarely been used as solid organic semiconductors. Cyanine dyes form aggregates with extremely efficient exciton transport, extraordinary strong absorbance, important non-linear optical coefficients as well as excited state quenching. These properties would be of great interest in the field of organic semiconductors, but can only be exploited when aggregates form in a controlled manner in thin films.The project is a continuation of the SNF projects 200021_132502 and 200020_149127 on “Structured Templates for Dye Aggregation and Crystallization for Applications in Photovoltaics and Photonics”. In the latter project we discovered a new growth method for single crystals of cyanine dyes. We now propose to self-assemble cyanine dyes into aggregates by applying that growth method.In a first step we will continue to investigate the basic mechanisms of nucleation, growth and polymorphic transformations. In a second step we will manipulate crystal growth and structure with surfaces showing a surface energy pattern fabricated by micro contact printing. Crystallization on these surfaces will be directed towards the growth of J-aggregate crystals. We will fully characterize the electro-optical properties of the thin film crystals and relate these properties to the structure. The project aims at establishing collaborations to find applications in opto-electronics for cyanine dye crystal films.