Electroluminescence properties of a non-conjugated polymer poly[2,5-benzoxazolediyl[2,2,2-trifluoro-1-(trifluoromethyl)-ethylidene]-5,2-benzoxazolediyl[2,5-bis(decyloxy)-1,4-phenylene]] (6FPBO-OD)

Light-blue-emitting devices were fabricated from a non-conjugated polymer poly[2,5-benzoxazolediyl[2,2,2-trifluoro-1-(trifluoromethyl)-ethylidene]-5,2-benzoxazolediyl[2,5-bis(decyloxy)-1,4-phenylene]] (6FPBO-OD). Top brightness and electroluminescence (EL) internal quantum yield reach 204 cd/m2 (at 17 V with a Mg:Ag cathode) and 0.86% (at 12 V with an Al cathode), respectively, in the double-layer devices with polymer poly(9-vinylcarbazole) (PVK) used as a hole-transporting layer. This competitive performance, especially for a bluish polymer light-emitting device (LED), was achieved against the fact that the photoluminescence yields of this polymer are unusually low, which is explained in terms of fluorescence quenching excimer formation and intramolecular charge transfer. The understanding of the photophysical nature of this polymer and its link to the polymer structure provides significant implications for improving the electroluminescent properties of this type of non-conjugated polymer.