Authors: Rituparno Chowdhury, Marco D. Preuss, Hwan-Hee Cho, Joshua J. P. Thompson, Samarpita Sen, Tomi K. Baikie, Pratyush Ghosh, Yorrick Boeije, Xian Wei Chua, Kai-Wei Chang, Erjuan Guo, Joost van der Tol, Bart W. L. van den Bersselaar, Andrea Taddeucci, Nicolas Daub, Daphne M. Dekker, Scott T. Keene, Ghislaine Vantomme, Bruno Ehrler, Stefan C. J. Meskers, Akshay Rao, Bartomeu Monserrat, E. W. Meijer, Richard H. Friend
Published: 2025-03-13
Source: Full article
Current organic light-emitting diode (OLED) technology uses light-emitting molecules in a molecular host. We report green circularly polarized luminescence (CPL) in a chirally ordered supramolecular assembly, with 24% dissymmetry in a triazatruxene (TAT) system. We found that TAT assembled into helices with a pitch of six molecules, associating angular momentum to the valence and conduction bands and obtaining the observed CPL. Cosublimation of TAT as the “guest” in a structurally mismatched “host” enabled fabrication of thin films in which chiral crystallization was achieved in situ by thermally triggered nanophase segregation of dopant and host while preserving film integrity. The OLEDs showed external quantum efficiencies of up to 16% and electroluminescence dissymmetries ≥10%. Vacuum deposition of chiral superstructures opens new opportunities to explore chiral-driven optical and transport phenomena.