Modulation of the photophysical properties by molecular design of carbene-metal-amide materials for highly efficient OLEDs

Thermally activated delayed fluorescence (TADF) has emerged as a competitive approach to provide a route towards highly energy-efficient OLED lighting and display applications. Our results show that organometallic complexes and in particular carbene metal amide materials (CMA) are an effective platform to control fundamental photophysical properties such as excited state lifetime and photoluminescence quantum yields. Comparison and key differences of the various CMA materials will be discussed to showcase the role of the metal and organic ligands, steric and electronic factors or result of their interplay. On the basis of CMA materials, we demonstrate the molecular design strategy based on twisted and tilted emitter geometries between donor and acceptor ligands to realize highly efficient TADF materials beyond the conventional co-planar approach applied in organic materials.