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Organic electrochemical transistors are fabricated on a poly(L-lactide-co-glycolide) substrate. Fast and sensitive performance of the transistors allows recording of the electrocardiogram. The result paves the way for new types of bioelectronic interfaces with reduced invasiveness due to bioresorption and soft mechanical properties. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Solution prepared single crystal organic field-effect transistors (OFETs) combine low-cost with high performance due to structural ordering of molecules. However, in organic crystals polymorphism is a known phenomenon, which can have a crucial influence on charge transport. Here, the performance of solution-prepared single crystal OFETs based on two different polymorphs of dithiophene-tetrathiafulvalene, which were investigated by confocal Raman spectroscopy and X-ray diffraction, are reported. OFET devices prepared using different configurations show that both polymorphs exhibited excellent device performance, although the a-phase revealed charge carrier mobility between two and ten times higher in accordance to the closer stacking of the molecules.

Molecular multifMolecular multifunctional materials have potential applications in many fields of technology, such as electronics, optics and optoelectronics, information storage, sensing, and energy conversion and storage. These materials are designed exhibit enhanced properties, and at the same time are endowed with functional groups that control their interactions, and hence self-organization, into a variety of supramolecular architectures. Since most of the multifunctional materials are soluble, lithographic methods suitable for solutions are attracting increasing interest for the manufacturing of the new materials and their applications. The aim of this paper is to highlight some of the recent advances of solution-based fabrication of multifunctional materials. We explain and examine the principles, processes, materials, and limitations of this class of patterning techniques, which we term unconventional wet lithographies (UWLs). We describe their ability to yield patterns and structures whose feature sizes range from nanometers to micrometers. In the following sections, we focus our attention on micromolding in capillaries, lithographically controlled wetting, and grid-assisted deposition, the most used methods demonstrated to lead to fully operating devices.

Polyaniline is doped with an Alq(3) homologue endowed with sulfonic acid functionalities. The design of the dopant, which favors the formation of a crosslinked network between the polymer chains, along with its semiconducting electrical properties, highly enhance charge transport inside the amorphous phase of the material (see figure).

The luminescence of conjugated materials has been intensively investigated because of the perspective of a new generation of flat-panel electroluminescent displays based on molecular [1] and polymer thin films. [2] Charge transport and energy-transfer processes in organic thin films are different with respect to conventional electroluminescent materials. [3‐5] The transfer of the exciton energy within the electronic manifold, which occurs upon charge recombination, is highly sensitive to the local molecular environment. [6,7] Therefore, luminescence eventually depends on how the molecules pack in the solid into aggregates, rather than being an intrinsic property of the material. [8,9] Here we discuss the energy-transport processes in systems where the interplay between self-organization and kinetics of growth causes the molecules to form aggregates with a different packing with respect to the well-ordered crystalline material. [10‐12] We show that in growth regimes where both the purity of the material and the conditions of growth are highly controlled, the spectral features of photoluminescence can be correlated to precise structural topologies. As a consequence, the emission from a thin film can be spectrally tuned by changing the film morphology. Moreover, we show that the nature of the aggregate states in a prototypical molecular material can be ascribed to the coalescence of neighboring domains. We use the oligomer approach, which is useful when the interplay between molecular order and intrinsic optical response of the conjugated material is the focus of the investigation. A conjugated oligomer, such as a-sexithienyl (T6), [13]