Abstract
Here we report organic light-emitting diodes incorporating linear and cyclic porphyrin hexamers which have red-shifted emission (lambda(PL) = 873 and 920 nm, respectively) compared to single porphyrin rings as a consequence of their extended pi-conjugation. We studied the photoluminescence and electroluminescence of blends with poly(9,9'-dioctylfluorene-alt-benzothiadiazole), demonstrating a high photoluminescence quantum efficiency of 7.7% for the linear hexamer when using additives to prevent aggregation and achieving high color purity near-infrared electroluminescence.