Benzene-cored fluorophors with TPE peripheries: facile synthesis, crystallization-induced blue-shifted emission, and efficient blue luminogens for non-doped OLEDs

Abstract

In this paper, three benzene-cored fluorophors with TPE moiety peripheries (PhTPE, Ph2TPE and Ph3TPE), are synthesized and their thermal, optical and electronic properties are investigated. All of them are nearly non-emissive when readily dissolved in solution but become highly emissive in the aggregate state, making them promising candidates for optoelectronic materials. Non-doped OLEDs with these luminogens as emissive layers exhibit sky-blue to deep blue emissions from 488 to 457 nm with L_max, η_{C, max} and η_{P, max} up to 3966 cd m⁻², 5.0 cd A⁻¹ and 3.87 lm W⁻¹, respectively, owing to the twisted conformation between the benzene core and TPE units.