Stretchable electroluminescent (EL) polymers are the key components for realizing skin-like displays and optical bio-simulations, which can offer unique functionality for information visualization, wirelessly signal/power transmission, and medical therapies. However, in contrast to other types of stretchable devices, such as sensors and transistors, stretchable EL devices have lagged behind in terms of combining high stretchability with high EL efficiency. All stretchable emitters reported to date have been based on “first-generation” EL polymers that can only harness the singlet excitons with a theoretical quantum yield of 25%. In this work, we present a material design concept for imparting the stretchability onto “third-generation” EL polymers that can harness all the excitons through thermally activated delayed fluorescence (TADF), thereby with a theoretical near-unity quantum yield. Our novel design concept for such stretchable light-emitting polymers is the backbone insertion of flexible, linear units between TADF units, which, as shown both experimentally and theoretically, provides very effective strain dissipation for stretchability without causing any sacrifice to the EL performance. Therefore, enabled by the highly efficient TADF processes and extraordinary stretchability, record-high external quantum efficiency (EQE) is achieved even at 100% strain. Demonstrated by the fully stretchable organic light-emitting diodes (OLEDs), the stretchable TADF polymers provide an unparalleled path towards achieving all the desired EL and mechanical characteristics, including high efficiency, brightness, switching speed, stretchability, and low driving voltage.

High-efficiency electroluminescent polymers for fully stretchable organic light-emitting diodes

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.