Ultrastable supramolecular self-encapsulated wide-bandgap conjugated polymers for large-area and flexible electroluminescent devices

Journal article

Controlling chain behavior through smart molecular design provides the potential to develop ultrastable and efficient deep-blue light-emitting conjugated polymers (LCPs). Herein, a novel supramolecular self-encapsulation strategy is proposed to construct a robust ultrastable conjugated polydiarylfluorene (PHDPF-Cz) via precisely preventing excitons from interchain cross-transfer/coupling and contamination from external trace H2 O/O2 . PHDPF-Cz consists of a mainchain backbone where the diphenyl groups localize at the 9-position as steric bulk moieties, and carbazole (Cz) units localize at the 4-position as supramolecular π-stacked synthon with the dual functionalities of self-assembly capability and hole-transport facility. The synergistic effect of the steric bulk groups and π-stacked carbazoles affords PHDPF-Cz as an ultrastable property, including spectral, morphological stability, and storage stability. In addition, PHDPF-Cz spin-coated gelation films also show thickness-insensitive deep-blue emission with respect to the reference polymers, which are suitable to construct solution-processed large-scale optoelectronic devices with higher reproducibility. High-quality and uniform deep-blue emission is observed in large-area solution-processed films. The electroluminescence shows high-quality deep-blue intrachain emission with a CIE (0.16, 0.12) and a very narrow full width at half-maximum of 32 nm. Finally, large-area and flexible polymer light-emitting devices with a single-molecular excitonic behavior are also fabricated. The supramolecular self-encapsulation design provides an effective strategy to construct ultrastable LCPs for optoelectronic applications.

Authors: Lin, J; Liu, B; Yu, M; Wang, X; Lin, Z

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Wiley
• Journal: Advanced Materials
• Volume: 31
• Issue: 1
• Pages: 1804811
• Publication date: 2018-10-29
• Acceptance date: 2018-09-17
• DOI: 10.1002/adma.201804811
• EISSN: 1521-4095
• ISSN: 0935-9648
• Pmid: 30370608
• Language: English
• Keywords: self-encapsulated strategy; polyfluorene; ultrastable; deep blue; flexible electroluminescent devices