Triphenylamine Spirofunctionalized Light‐Emitting Conjugated Polymer with an Ultradeep‐Blue Narrowband Emission for Large‐Area Printed Display

Abstract

Emerging printed large‐area polymer light‐emitting diodes (PLEDs) are essential for manufacturing flat‐panel displays and solid lighting devices. However, it is challenging to obtain large‐area and stable ultra‐deep‐blue PLEDs because of the lack of light‐emitting conjugated polymers (LCPs) with robust deep‐blue emissions, excellent morphological stabilities, and high charging abilities. In this study, a novel unsymmetrically substituted polydiarylfluorene (POPSAF) was obtained with stable narrowband emission for large‐area printed displays via triphenylamine (TPA) spiro‐functionalization of LCPs. POPSAF films show narrowband and stable ultra‐deep‐blue emission with a full width at half maximum (FWHM) of 36 nm, associated with their intrachain excitonic behavior without obvious polaron formation. Compared to controlled PODPF, excellent charge transport was observed in the POPSAF films because of the intrinsic hole transport ability of the TPA units. Large‐area PLEDs were fabricated via blade‐coating with an emission area of 16 cm2, which exhibited uniform ultra‐deep‐blue emission with a FWHM of 36 nm and corresponding Commission internationale de l’éclairage (CIE) coordinates of (0.155, 0.072). These findings were attributed to the synergistic effects of robust emission, stable morphology, and printing capacity. Finally, preliminary printed passive matrix PLED displays with 20 × 20 pixels monochromes were fabricated, confirmed the effectiveness of spiro‐functionalization in optoelectronics.This article is protected by copyright. All rights reserved