Exciplex polymer with strong AIE for constructing fully-solution-processed organic light-emitting diodes with 100-fold efficiency improvement compared to physically blended exciplex

Abstract

Transferring the exciplex concept to polymeric systems should be a productive way to unify two functional components to obtain a powerful union. Here, we demonstrate that an exciplex polymer can be constructed by a strategy of synthetic or in situ polymerization of styrene functionalized components. The resulting flexible exciplex polymer P–TRZ–TPA exhibits small singlet–triplet splitting (ΔE_ST) and strong aggregation-induced emission (AIE) properties, which are beneficial for a low turn-on voltage and high luminance of organic light-emitting diodes (OLEDs). Importantly, the efficient orthogonal solvent resistance of P–TRZ–TPA ensures the fabrication of fully-solution-processed phosphorescence devices with a maximum current efficiency of 20.8 cd A⁻¹, which is 100-fold that of the control device host with a small molecule mixture exciplex. Such an exciplex polymer concept can be expanded to various types of donors and acceptor units to further enrich the category of exciplex systems and extend the exciplex application field, especially for solution-processed multilayer electronic devices.