Dual‐Mediated Aggregate Electrochemiluminescence of Rubrene

ABSTRACT Electrochemiluminescence (ECL) populates the luminescent excited states through electrochemical reactions. It is challenging to mediate the ECL behaviors of molecular nanoaggregates because both the photophysical and electrochemical properties usually deteriorate in aggregate states. In this work, we demonstrate an unprecedented supramolecular strategy that simultaneously modulates both the photophysical and electrochemical factors governing ECL. The ECL performance of rubrene (RUB) nanoaggregates can be significantly enhanced through the incorporation of hole‐transporting molecules as both redox and photophysical mediators. A balanced state, inhibiting the singlet fission (SF) and retaining the triplet–triplet annihilation (TTA), was achieved for RUB, which not only reduced the quenching of luminescent singlet state excitons but also well utilized the electrochemically generated triplet state excitons. The redox‐mediating properties of hole‐transporting molecules toward co‐reactant not only promote the formation of excitons but also reduce the luminescent potential. The RUB nanoaggregates showed significantly enhanced photoluminescence quantum efficiency (2.3‐fold) and ECL intensity (50‐fold) in aqueous conditions and were demonstrated as promising ECL imaging probes. This work opens up a new avenue for the preparation of ECL nano‐emitters with high‐brightness in aqueous conditions.