题目： | stepwise planarizing geometries of d–a type red thermally activated delayed fluorescence molecules in condensed states toward high-efficiency red/nir oleds |
作者： | hui wang1, sen lin1, jia-xiong chen2, xiao-yao hao1, xiao-chun fan1, yi-zhong shi3, jia yu1*, xian-kai chen1,5*, kai wang1,4*, and xiao-hong zhang1,5* |
单位： | 1institute of functional nano & soft materials (funsom), collaborative innovation center of suzhou nanoscience and technology, soochow university, 199 ren-ai road, suzhou 215123, china. 2school of chemical engineering and light industry, guangdong university of technology, guangzhou, guangdong, 510006, p. r. china. 3school of materials science and engineering, suzhou university of science and technology, suzhou, jiangsu 215009, p. r. china. 4jiangsu key laboratory for carbon-based functional materials & devices, soochow university, suzhou, 215123, jiangsu, p. r. china. 5jiangsu key laboratory of advanced negative carbon technologies, soochow university, suzhou, 215123, jiangsu, p. r. china. |
摘要： | quasiplanar donor–acceptor (d–a) thermally activated delayed fluorescence (tadf) molecules are appealing candidates for efficient red/near-infrared (nir) emitters but have not been realized. herein, for the first time, a stepwise approach to achieve this goal via a spiro-locked c─c covalent bond linking strategy combined with the subtle management of intermolecular c─h···cn noncovalent bonds in condensed states is presented. this synergetic effect enables the newly developed molecule, dcn-sac, to not only attain nearly unity photoluminescence quantum yield, with a horizontal dipole ratio of up to 89% at 5 wt% doped conditions but also achieve a quasiplanar configuration with high-exciton-harvesting j-aggregates under neat condensed conditions. the optimized organic light-emitting diode (oled) using dcn-sac as the dopant furnishes a topmost external quantum efficiency (eqe) of 38.7% at 631 nm among all red oleds based on tadf materials. more importantly, a dcn-sac-based nondoped oled affords a remarkable eqe of 12.6% with an emission peak at 730 nm, which sets a record-breaking value among all previously reported nondoped tadf devices in the similar emission region. these findings reveal the effectiveness and great potential of stepwise planarity, presenting a new paradigm for developing high-efficiency red/nir tadf oleds. |
影响因子： | 18.5 |
分区情况： | 一区 |
链接： |
责任编辑：郭佳