Intrinsically Flexible and Aging Resistant Fluorene‐Based Rod‐Coil Copolymer for Bendable Deep‐Blue PLEDs

Abstract

In the field of flexible light‐emitting display, goal‐oriented intelligent molecular design is used to control various behaviors of molecules, which provides potential for the development of flexible light‐emitting conjugated polymers (LCPs). The introduction of non‐conjugated units into polymer molecules is a key prerequisite for realizing the intrinsic flexibility, but its easy interchain slip will also lead to the formation of interchain excited states, which is detrimental to the efficiency of light‐emitting diodes. Herein, two kinds of fluorene‐based rod‐coil copolymer with stable deep blue emission characteristics is presented and with Commission Internationale de L'Eclairage (CIE) coordinates of (0.18, 0.14) and (0.15, 0.09), respectively. Surprisingly, the copolymer films show efficient blue emission even at 100% tension. Meanwhile, the rod‐coil copolymer possesses better aging resistance compared to rigid π‐conjugated counterparts. Finally, both rigid and flexible light‐emitting diodes based on rod‐coil copolymer exhibit stable deep blue emission, and the G2‐based PLED with CIE coordinates of (0.16, 0.08), which approach National Television System Committee standard blue specification. These results confirm the validity of rod‐coil copolymer design strategy in constructing inherently flexible polymers with deep blue emission, which have great application potential in flexible PLEDs.

Recent Research Advances in Textile-Based Flexible Power Supplies and Displays for Smart Wearable Applications

“…(c) Photograph of the PLED display in the bending state. Reproduced with permission from ref . Copyright 2023 Wiley-VCH GmbH.…”

“…surface, which is currently the best choice for realizing largescale printing of PLEDs.70−73 Li H74 et al demonstrated that fluorene-based rod−coil copolymers with deep blue emission properties also emit blue light stably under 100% tension. Both rigid and flexible lightemitting diodes based on rod−coil copolymers exhibited stable deep blue emission, and the CIE coordinates of G2-based PLEDs were (0.16, 0.08), suggesting that rod−coil copolymers have the potential to be utilized in PLEDs (Figure8a−c).…”