Highly Efficient Supramolecular Nucleating Agents for Poly(3-hexylthiophene)

Abstract

Controlling the solid-state morphology of semiconducting polymers is crucial for the function and performance of optoelectronic and photonic devices. Nucleation is a commonly used and straightforward approach to tailor the solid-state morphology of semi-crystalline polymers. However, efficient nucleating agents for semiconducting polymers are still rare. Here, we present a conceptual approach to tailor supramolecular nucleating agents for the semiconducting polymer, poly(3-hexylthiophene) (P3HT). Using this approach, we developed a class of supramolecular nucleating agents, which can achieve outstanding nucleation efficiencies of more than 95% at concentrations as low as 0.1 wt %. Such efficiencies can be achieved by combining an exceptionally high epitaxial match with highly regularly arranged donor−acceptor interactions between the nucleating agent and the polymer. Notably, the supramolecular agents do not induce trap states in thin films of P3HT and are beneficial for the film stability by controlling the solid-state morphology. We anticipate that this approach can be transferred to other semi-crystalline conjugated polymers, resulting in defined solid-state morphologies.

Designing a Length‐Modulated Azide Photocrosslinker to Improve the Stretchability of Semiconducting Polymers

“…[ 60–62 ] Nucleating agents can promote the microstructure formation, i.e., crystallization, of conjugated polymers during the film forming process and the thermal annealing process. [ 60,63,64 ] Additional GIXD results for non‐annealed DPPDTT/1‐NIPS films provide the evidence that 1‐NIPS promotes the crystallization of DPPDTT during thermal annealing process (Figure S29, Supporting Information). For RR‐P3HT films, added 1‐NIPS molecules were also located at amorphous regions and changed the crystalline ordering depending on the added amount of 1‐NIPS (Figure S30 and Table S4, Supporting Information).…”

“…2D‐GIXD was measured with a critical angle of each sample (beam intensity 11.06 keV) at Pohang Accelerator Laboratory beamlines 3C and 9A. [ 64 ] DMTA was conducted using TA Instruments Q850 with a film tensile kit. Samples were prepared by drop‐casting high‐concentration (20 mg·mL −1 ) polymer solutions in chloroform to achieve suitable evaporation on both sides of the glass fiber mesh on an N 2 environment hot plate (≈ 50 °C) and dried in a vacuum oven overnight at the same temperature to drive off residual water molecules and solvents.…”

Directed Gradients in the Excited-State Energy Landscape of Poly(3-hexylthiophene) Nanofibers

“…Heterogeneous nucleating agents (NAs) are known to provide an epitaxial surface from which the polymer crystallization is initiated, and subsequently, crystal growth proceeds in a defined manner. , Achieving very densely packed and oriented nanofibers of P3HT requires NAs with a highly regular surface and a large number of nucleation sites. In our recent work, we have shown that a supramolecular NA based on N , N ′-1,4-phenylenebis­[4-pyridinecarboxamide] (compound 1 , see Scheme ) is an excellent nucleating agent for the oriented crystallization of P3HT …”

“… a The molecular design combines the ability to form stable supramolecular aggregates via hydrogen bonding of the amide linkages, resulting in epitaxial surfaces with the ability to form attractive pyridine–thiophene interactions to nucleate P3HT …”

“…Here, we exploit defect fractionation during the growth of nanofibers based on a conjugated polymer to realize a gradient in the excited-state energy landscape over micrometer distances. We employ a highly efficient ribbon-like supramolecular nucleating agent (NA) for the controlled crystallization of the extensively studied and well-understood poly­(3-hexylthiophene), P3HT, − into nanofibers. The resulting NA/P3HT superstructures, resembling shish-kebab-like structures, , with their highly aligned and oriented micrometer-long P3HT nanofibers allow us to use hyperspectral imaging, i.e., spatially resolved absorption and emission spectroscopy.…”