Dinuclear　Ir(iii)　complexes　have　recently　emerged　with　great　promise　for　organic　electroluminescent　devices　owing　to　their　unique　merits　such　as　increased　spin-orbit　coupling　and　adjustable　photophysical　properties.　However,　most　of　them　require　sophisticated　doping　processes　for　their　engineering,　resulting　in　high　production　costs.　Herein,　we　developed　novel　dinuclear　Ir(iii)　complexes,　which　become　weak　phosphors　in　solution　but　exhibit　intensified　emission　in　the　solid　state.　The　intermolecular　interaction-caused　quenching　was　suppressed　perfectly,　and　the　carrier　transport　abilities　were　modulated　simultaneously,　leading　to　high　emission　efficiencies　in　the　neat　film　and　balanced　charge　carrier　transport.　The　green-emitting　single-layer　nondoped　device　achieved　promising　efficiencies　with　an　external　quantum　efficiency　(EQE)　of　11.6%　and　current　efficiency　(CE)　of　40.0　cd　A-1.　The　orange-emitting　device　realized　an　EQE　of　12.9%　and　CE　of　38.4　cd　A-1,　which　are　the　highest　efficiencies　reported　to　date　for　solution-processed　single-layer　nondoped　devices　and　even　comparable　to　that　of　most　reported　multilayer　doping　devices.　©　The　Royal　Society　of　Chemistry.