Solid‐State Supramolecular Organization of Polythiophene Chains Containing Thienothiophene Units

Abstract

We use molecular modeling and the simulation of X‐ray diffraction patterns to determine the molecular packing of a thiophene‐based polymer showing exceptionally high field‐effect mobilities (up to 1 cm2 V−1 s−1). We focus on the organization of the polymer chains in lamellae and the orientation of these crystalline domains with respect to the substrate in thin films. The analysis is supported by XRD and NEXAFS experiments and is complemented by calculating intermolecular transfer integrals, which govern the charge mobility.

Multi-Scale Modeling of Bulk Heterojunctions for Organic Photovoltaic Applications

“…Simulations of the two polymer melts show that the structural properties in PBTTT facilitate both intraand inter-chain charge transport compared with P3HT, due to greater degree of planarity, closer and more parallel stacking of the thiophene and thienothiophene rings, and possible interdigitation of the dodecyl side chains. X-ray diffraction studies have shown that PBTTT indeed forms interdigitated alkyl side chains (Brocorens et al, 2009;Kline et al, 2007). Thus, the crucial role played by the bulky dodecyl side chain and thienothiophene ring, respectively, in determining intra-chain and inter-chain structural order is clarified through these simulations .…”

Charge Transport in Organic Semiconductors: A Multiscale Modeling

“…This explains why the density does not change much from NI to I (1.2 versus 1.3). NI is much less stable than I, by 14.7 kcal mol À1 per monomer unit [65]. PBTTT is therefore expected to be interdigitated (see middle of Figure 1.7).…”

“…An original approach validating the use of force field calculations via the simulation of corresponding X-ray diffraction patterns is also introduced here (see Ref. [65] for the original reference).…”

“…In the previous case, the force field calculations were exploited to depict the lattice dynamics; however, they also proved useful in modeling the packing of organic semiconductors into organized nanostructures, as illustrated in Section 1.3 focusing on the molecular packing of tetrathiafulvalene (TTF) derivatives and the resulting charge transport properties [64]. Since it is highly desirable to validate the structures provided by force field calculations, we introduce in Section 1.4 an original approach where X-ray diffraction spectra are generated on the basis of the calculated structures to be compared to corresponding experimental spectra; this is illustrated here for polythiophene chains incorporating thienothiophene units in order to discuss their hole transport properties [65]. Section 1.5 further illustrates through a study of charge transport along one-dimensional stacks made of phthalocyanine (PC) derivatives that lattice dynamics can generate structural defects that are dynamic in nature [66].…”

Integration of electro-active π-conjugated units in nanosegregated liquid-crystalline phases

“…The self-organization of π-conjugated units also affects the electronic properties of organo-gels [12][13][14][15] and conductive polymers. [16][17][18] Unlike organic crystals and amorphous solids, supramolecular structures can be constructed in liquid crystal phases using nanosegregation between immiscible moieties built into LC molecules. 19 Kato and coworkers reported one-and two-dimensional ionic conduction in nanosegregated supramolecular liquid crystals.…”