Interface-Dependent Aggregation-Induced Delayed Fluorescence in Bottlebrush Polymer Nanofibers

Abstract

Bottlebrush copolymers provide a covalent route to multicompartment nanomaterials that remain nanosegregated regardless of environmental conditions. This is particularly advantageous when combining polymers for optoelectronics, where the ability to control the interface between multiple chemically distinct polymers can be key to a device’s function. Here we prepare bottlebrush nanofibers from an acridine- and triazine-based donor/acceptor pair, which have been shown to exhibit thermally activated delayed fluorescence (TADF) via through-space charge transfer (TSCT). By controlling the morphology of the donor and acceptor domains within the bottlebrush, random, miktoarm, and block bottlebrush morphologies are obtained. Using these materials, nanofibers may be prepared which (i) strongly exhibit TSCT TADF; (ii) exhibit switchable TSCT TADF based on aggregation of the fibers; or (iii) preserve the properties of the original donor and acceptor components. This work demonstrates that a bottlebrush strategy may be used to either force or prevent interactions between chemically dissimilar optoelectronic polymers in blended thin films. In this way, we establish a convenient method for either maximizing or minimizing donor–acceptor interactions in semiconductor polymer blends, using different arrangements of the same building blocks within a bottlebrush nanofiber.

Through‐space charge transfer polymers for solution‐processed organic light‐emitting diodes

“…Under this circumstances, living polymerization methods with controlled and narrow-distributed molecular weights, regulable sequence structures, and tailorable end groups are highly desired for synthesis of TSCT polymers. [67] We believe that under the efforts of researchers in chemistry, physics, and material science, TSCT polymers will become one of the most important subjects in the future research field of luminescent polymers and solutionprocessed OLEDs. In addition, as a kind of π-stacked donoracceptor system with long-lived delayed fluorescence (0.1-100 µs) derived from triplet states, TSCT polymers should also be useful in other applications such as oxygen sensing and time-resolved fluorescence imaging.…”

“…Under this circumstances, living polymerization methods with controlled and narrow‐distributed molecular weights, regulable sequence structures, and tailorable end groups are highly desired for synthesis of TSCT polymers. [ 67 ]…”

Through‐Space Charge‐Transfer Polynorbornenes with Fixed and Controllable Spatial Alignment of Donor and Acceptor for High‐Efficiency Blue Thermally Activated Delayed Fluorescence

“…Up to now,only few polymers based on conjugated donor-acceptor structure have been reported for blue emission with TADF effect. [14,16,[19][20][21] Different from luminescent polymers with TBCTemission from conjugated donor-acceptor structures,t hrough-space charge transfer (TSCT) polymers with spatially-separated donors and acceptors,s uch as polystyrenes with separated donors and acceptors in side chain [47,48] and bottlebrush polymers consisting of macromonomer donor and acceptor strands, [49] have been reported by our and others groups.This strategy using through-space donor and acceptor interactions in the polymer design has two advantages.F irst, the large bathochromic shift of emission can be avoided owing to the conjugation interruption, which is favorable for blue emission. Second, the electron cloud overlap between donor and acceptor can be reduced, beneficial for reducing DE ST and achieving TADF effect.…”

Through‐Space Charge‐Transfer Polynorbornenes with Fixed and Controllable Spatial Alignment of Donor and Acceptor for High‐Efficiency Blue Thermally Activated Delayed Fluorescence

“…Different from luminescent polymers with TBCT emission from conjugated donor‐acceptor structures, through‐space charge transfer (TSCT) polymers with spatially‐separated donors and acceptors, such as polystyrenes with separated donors and acceptors in side chain [47, 48] and bottlebrush polymers consisting of macromonomer donor and acceptor strands, [49] have been reported by our and others’ groups. This strategy using through‐space donor and acceptor interactions in the polymer design has two advantages.…”