Simple silole-containing polyfluorene for white electroluminescence with simultaneous blue, green, and red emission

Abstract

Novel conjugated silole-containing polyfluorenes, with green- and red-emissive siloles on the backbone of the blue-emissive polyfluorene are synthesized for white light electroluminescence (EL) from a single polymer with simultaneous red, green, and blue (RGB) emission. TheCIE coordinates (0.33, 0.36) of the white light EL spectra are very close to that for pure white light (0.33, 0.33). The EL spectra are also quite stable at different applied voltages or brightness. The relative intensities for the three RGB peaks, at 450, 505, and 574 nm, were 0.94, 1, and 0.97, respectively, which demonstrates a balanced simultaneous RGB emission. A maximum luminous efficiency of 2.03 cd-A -1 for a brightness of 344 cd · m 2, and a luminous efficiency of 1.86 cd ·A-1 for a more practical brightness of 2 703 cd · m-2, were achieved. © 2007 WILEY-VCH Verlag GmbH & Co. KGaA.