White light emission from two blue emitters of an equimolar (1:1) blend in single-layer device

A white light emission was observed from a single-layer emitting system consisting of an equimolar blend of two blue emitters of a bipolar oligomer, 9,9-spirobifluorene-centered bioxadiazole (303) and polyvinylcarbazole (PVK), featuring a single broad emission (ranging in 400-800 nm), which is distinctly different from those of large PVK-fraction blends (λem ≈ 490 nm) and that of pristine 303 (λem ≈ 555 nm) as well.