Mononuclear silver complexes for efficient solution and vacuum-processed OLEDs

Carbene metal amides (CMAs) are a new class of highly efficient light-emitting molecules based on a linear donor-metal-acceptor geometry. Here we report the synthesis, structure, photo- and electroluminescence of carbene silver carbazolato complexes, (AdL)Ag(Cz) [AdL = adamantyl-substituted cyclic (alkyl)(amino)carbene; Cz = carbazolate (1) and 3,6-tBu2Cz (2)]. They display green emission with photoluminescence quantum yields of up to 74%. Efficient mixing of triplet and singlet excited states is observed, with sub-microsecond thermally activated radiative triplet lifetimes. These complexes provide prototype organic light-emitting diodes (OLEDs) based exclusively on silver emitters, with external quantum efficiencies of up to 14%