Binary Superlattices of Infrared Plasmonic and Excitonic Nanocrystals.

Self-assembled superlattices of nanocrystals offer exceptional control over the coupling between nanocrystals, similar to how solid-state crystals tailor the bonding between atoms. By assembling nanocrystals of different properties (e.g.

Dopant-Induced Ordering of Amorphous Regions in Regiorandom P3HT.

Despite the fact that molecular doping of semiconducting polymers has emerged as a valuable strategy for improving the performance of organic electronic devices, the fundamental dopant-polymer interactions are not fully understood. Here we use 2-D grazing incidence wide-angle X-ray scattering (GIWAXS) to demonstrate that adding oxidizing small-molecule dopants, such as 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (FTCNQ) and FeCl, into the amorphous conjugated polymer, regiorandom poly(3-hexylthiophene-2,5-diyl) (RRa-P3HT), improves polymer ordering and induces a change in domain orientation from isotropic to mostly edge-on. Doping thus causes RRa-P3HT to behave similarly to the more ordered regioregular P3HT.

Poly(3-alkylthiophene)- block-poly(3-alkylselenophene)s: Conjugated Diblock Co-polymers with Atypical Self-Assembly Behavior.

Understanding self-assembly behavior and resulting morphologies in block co-polymer films is an essential aspect of chemistry and materials science. Although the self-assembly of amorphous coil-coil block co-polymers is relatively well understood, that of semicrystalline block co-polymers where each block has distinct crystallization properties remains unclear. Here, we report a detailed study to elucidate the rich self-assembly behavior of conjugated thiophene-selenophene (P3AT- b-P3AS) block co-polymers.

Overcoming Film Quality Issues for Conjugated Polymers Doped with F4TCNQ by Solution Sequential Processing: Hall Effect, Structural, and Optical Measurements.

We demonstrate that solution-sequential processing (SqP) can yield heavily doped pristine-quality films when used to infiltrate the molecular dopant 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) into pure poly(3-hexylthiophene) (P3HT) polymer layers. Profilometry measurements show that the SqP method produces doped films with essentially the same surface roughness as pristine films, and 2-D grazing-incidence wide-angle X-ray scattering (GIWAXS) confirms that SqP preserves both the size and orientation of the pristine polymer's crystallites. Unlike traditional blend-cast F4TCNQ/P3HT doped films, our sequentially processed layers have tunable and reproducible conductivities reaching as high as 5.