Intermolecular charge-transfer aggregates enable high-efficiency near-infrared emissions by nonadiabatic coupling suppression

Pursuing purely organic materials with high-efficiency near-infrared(NIR) emissions is fundamentally limited by the large nonradiative decay rates(knr) governed by the energy gap law. To date, reported endeavors to decelerate knrare mainly focused on reducing the electron-vibration coupling with the electronic nonadiabatic coupling assumed as a constant. Here, we demonstrated a feasible and innovative strategy by employing intermolecular charge-transfer(CT) aggregates(CTA) to realize high-efficiency NIR emissions via nonadiabatic coupling suppression. The formation of CTA engenders intermolecular CT in the excited states;thereby, not only reducing the electronic nonadiabatic coupling and contributing to small knrfor high-efficiency NIR photoluminescence, but also stabilizing excited-state energies and achieving thermally activated delayed fluorescence for highefficiency NIR electroluminescence. This work provides new insights into aggregates and opens a new avenue for organic materials to overcome the energy gap law and achieve high-efficiency NIR emissions.