Novel efficient blue and bluish-green light-emitting polymers with delayed fluorescence

Abstract

We developed a novel highly efficient blue-light-emitting polymer (P0) containing the alternating electron-deficient diphenylsulfone and the electron-rich 4-octyloxy-aniline moieties, which was synthesized by a palladium catalyzed C–N coupling reaction. Photophysical and light-emitting device characterization confirmed the delayed fluorescence mechanism of this copolymer. A polymer light-emitting diode based on P0 exhibited pure blue emission with CIE coordinates of (0.16, 0.10), which has a maximum external quantum efficiency of 5.3%. In addition, a series of color-tunable polymers that exhibit delayed fluorescence with light emission ranging from sky blue to bluish green and improved efficiency were developed by incorporating a ditriphenylamine-functionalized triazine unit. Our strategy represents a novel approach for the construction of polymers with delayed fluorescence and high efficiency.