High Comprehensive Circularly Polarized Electroluminescence Performance Improved by Chiral Coassembled Host Materials

Abstract

Circularly polarized organic light‐emitting diodes are of great significance in 3D displays. However, achieving circularly polarized electroluminescence (CP‐EL) simultaneously with a large dissymmetry factor (gEL) and high efficiency still remains a formidable challenge. Herein, a facile and efficient strategy is developed for improving the performance of CP‐EL devices using device emitting layers of chiral coassembled helix nanofiber host materials. Chiral coassembled helix nanofiber host materials ((S‐/R‐2Cz)0.2‐(PFpy)0.8) could be smartly constructed through intermolecular π–π stacking interactions between the achiral conjugated pyridine‐based polymer acceptor (PFpy) and the chiral binaphthyl‐based donor (S‐/R‐2Cz). Significantly, the resulting chiral coassembled hosts (S‐/R‐2Cz)0.2‐(PFpy)0.8 greatly promote a commercially available achiral phosphorescence emitter to achieve solution‐processed red CP‐EL device performances at 620 nm with a high external quantum efficiency of 4.1% and a large |gEL| value of 0.014.

High Internal Phase Emulsion for Constructing Chiral Helical Polymer-Based Circularly Polarized Luminescent Porous Materials

“…Porous materials with micro–nano structures have aroused mounting interest as they display promising applications in adsorption/separation, optoelectronics, catalysis, drug delivery/release, together with energy storage, and so on. − On the other hand, the ever-rising significance of chirality is reflected in its universality in nature, from chiral amino acids to proteins and DNA possessing helical structures, as well as higher-level chirality. , By judiciously integrating porous materials with chirality, scientists have explored the chiral-associated uses of the resulting chiral porous materials in asymmetric catalysis, chiral separation, chiral sensing, enantioselective release, and chiral optoelectronics . In this regard, chiral porous materials capable of producing circularly polarized luminescence (CPL) have become a hot research topic in the past few years, ,, because CPL reflects the excited-state information of chiral materials, − thus providing a powerful platform for applications of porous materials in cutting-edge fields such as 3D display, asymmetric photocatalysis, sensing, and information encryption, − which is different from applications such as chiral separation that usually only reflects chiral ground-state information afforded by circular dichroism (CD). To date, different types of CPL porous materials have been elaborately developed, including metal–organic frameworks (MOFs), − covalent organic frameworks (COFs), − metal–organic cages (MOCs), , and porous organic cages (POCs). , The features of these porous materials include high surface areas and controllable pore microenvironments as well as diverse compositions.…”