Pentafluorophenoxy Boron Subphthalocyanine As a Fluorescent Dopant Emitter in Organic Light Emitting Diodes

A fluorinated phenopxy boron subphthalocyanine (BsubPc) is shown to function as a fluorescent dopant emitter in small molecule organic light emitting diodes (OLEDs). Narrow electroluminescence (EL) emission with a full width at half maximum of similar or equal to 30 nm was observed regardless of the host used indicating that this narrow EL is intrinsic to the BsubPc molecule. A bathochromic shift and the growth of a new EL peak at higher wavelengths with increasing doping concentration were found to be a result of molecular aggregation. Excitation of BsubPc by direct charge trapping as well as Forster resonant energy transfer were shown using different hot molecules. A maximum efficiency of 1.5 cd/A was achieved for a 4,4'-N,N'-dicarbazole- biphenyl (CBP) host.