Multi-resonance TADF in optical cavities: suppressing excimer emission through efficient energy transfer to the lower polariton states

Abstract

Thermally activated delayed fluorescence (TADF) emitters suffer from molecular aggregation that limits their applicability in light emitting devices. Aggregation-induced excimer formation often leads to a larger Stokes shift, broader emission spectrum, and reduced emission quantum yields, limiting emitter dye loading to a few weight percent in organic light emitting devices. Here, we demonstrate suppression of excimer emission by dispersing a synthesised multi-resonance TADF emitter dye (OQAO(mes)2) in a PMMA host matrix and embedding the host–guest photoactive layer into an optical cavity. Rabi splitting up to 0.24 eV is obtained at 35 wt% dye loading. Under the strong coupling regime, prom..