All-polymeric control of nanoferronics

Abstract

The centimeter-sized polymeric crystalline superstructures reveal charge transfer–controlled nanoferronic properties.

Chemically Driven Interfacial Coupling in Charge-Transfer Mediated Functional Superstructures

“…These results are consistent with the previous report that the polythiophene−C 60 CT superstructures are self-organized through the π−π conjugated interaction along the b-axis (crystal growth direction) and stacked in planar structures with the long chain axis (c-axis) nearly perpendicular to the substrate. 9 While the fluorescence emission is also polarized for the DDT-C 60 crystal, the BT-C 60 crystal shows no preferential emission polarization, consistent with the disordered nature of this material ( Figure S6e,f). Furthermore, the change in fluorescence from a single HT-C 60 crystal measured as an external electric potential is applied.…”

“…The distances between rings and their nn C 60 molecules at the DDT-C 60 interface are much larger than those at the HT-C 60 interface but follow a similar Gaussian distribution. 9 By contrast, the ring-C 60 distance distribution at the disordered BT-C 60 interface is much broader and irregular, with a larger proportion in small distances that tends to increase with increasing time (Figure 1h and Figure S12). While the head-to-head defects at the polymer−C 60 interface also increase the probability of short ring-C 60 distances, the effect is much less significant than the disordered initial condition ( Figure S14).…”

“…7,8 Recently, room-temperature multiferroicity in centimeter-sized crystalline charge-transfer superstructures, consisting of polymer−fullerene complexes, was achieved by the self-organization and molecular-packing induced charge order-driven ferroic coupling. 9 To take advantage of the complexity and tunability of this new class of organic functional materials, a comprehensive understanding of the relationship between structure and properties is important.Interfacial engineering has been widely used to tune the electronic and optical behaviors of polymer−fullerene-based CT devices, and materials-by-design criteria exhibit a strong dependence on their structural architecture as demonstrated by both experimental 10−14 and theoretical 15−19 studies. Typically, longer side chain lengths of polymers lead to higher fullerene mobility and thus a larger scale of phase separation that reduces the interfacial area for charge separation.…”

“…The proposed strategies in this study open up a new opportunity to chemically design organic CT materials for the development of all-organic interfacial electronics. 9,51 Methods. The details for the synthesis of the solution and the growth of the crystals can be found in part 1 of the Supporting Information.…”

Integrated Charge Transfer in Organic Ferroelectrics for Flexible Multisensing Materials

“…Multifunctional all‐organic sensors hold the promise of ubiquitous lightweight, flexible, and low‐cost solution processing. Among all organic materials, the unique charge transfer and the exchange interaction between donor and acceptor of organic charge‐transfer (CT) complexes and the bipolar properties of CT donor and acceptor enable them with multifunctionalities which can be tuned in a large scale by multiple external stimuli . The discovery of multiferroics in κ‐(BEDT‐TTF) 2 Cu[N(CN) 2 ]Cl (BEDT‐TTF stands for bis(ethylenedithio)tetrathiafulvalene) single crystal initiated the field of molecular multiferroics .…”