Photoactivated Circularly Polarized Luminescent Organic Radicals in Doped Amorphous Polymer
Pengfei She, Yanyan Qin, Yuxiang Zhou, Xiao-Kang Zheng, Feiyang Li, Shujuan Liu, Yun Ma, Qiang Zhao, Wai‐Yeung Wong
Abstract
Abstract Luminescent organic radicals, especially those with photoactivated circularly polarized luminescence (CPL) features, hold great significance for cutting‐edge optoelectronic applications, but their development still remains a challenge. In this study, we propose a novel strategy to achieve photoactivated CPL radicals by bonding two phosphine centers within an axial chiral system, yielding a compound of R/S ‐5,5‐bis(diphenylphosphino)‐4,4′‐bibenzo[d][1,3]dioxole ( R/S ‐BDP). The photoactivated R/S ‐BDP molecules in polymer matrix display a robust quantum yield of 19.8 % and a dissymmetry factor (g lum ) of 1.2×10 −4 , marking this work as the first example of photoactivated CPL radicals. Furthermore, the g lum is improved to 1.0×10 −2 by using a liquid crystal as host. Experimental and theoretical analyses reveal that R/S ‐BDP molecules, endowed with double phosphine cores in axial chirality, offer a direct way for intramolecular electron transfer upon photoirradiation. This leads to the generation of radical ionic pairs, which subsequently trigger the donor‐acceptor arrangement through intermolecular electron transfer, thereby resulting in stable radical emission. The extended photoactivated BDP‐F exhibits a remarkably high quantum efficiency of 57.8%. Ultimately, the distinctive photo‐responsive CPL radical luminescence has been successfully used for information displays and anti‐counterfeiting.