摘要
成膜性能优异的聚合物发光材料适宜于可溶液加工大尺寸显示及照明器件制作,赋予其热诱导延迟荧光(TADF)特征能够有效改善器件发光性能.本工作以苯环对位桥连三联吡啶的吖啶衍生物(ABTPy)为TADF单体、咔唑(Cz)衍生物为共聚单体,利用交叉偶联反应,控制TADF单体摩尔投料比为1%、5%、10%和50%,合成了4个主链为咔唑-吖啶给体/侧基为三联吡啶受体的共轭聚合物PCzABTPy1~PCzABTPy 50.低含量TADF单元聚合物溶液的光致发光光谱显示了低聚咔唑片段和TADF单元的双峰发射,发光峰位是420和488 nm,聚合物薄膜仅出现单峰发射,发光峰由470 nm红移至508 nm.聚合物瞬态荧光衰减光谱均包含纳秒级瞬时荧光(12~15 ns)和微秒级延迟荧光(1.3~4.8μs),证实聚合物具有TADF特性.以聚合物为发光层的非掺杂溶液加工电致发光器件实现了蓝光发射,发光波长位于452~484 nm.其中,PCzABTPy10发光器件展示了最优的发光性能,最大外量子效率(EQE)为9.4%,启亮电压为3.0 eV.在亮度1000 cd/m2时,器件EQE仍保持在7.6%.
Luminescent polymers are suitable for the fabrication of solution-processed large-scale display and lighting devices due to their superior film-forming ability,and can effectively improve the device performances while endowed with thermally activated delayed fluorescence(TADF)characteristic.In this work,four polymers with carbazole/acridine backbone donor and terpyridine pendant acceptor,named PCzABTPy1‒PCzABTPy50,are synthesized by using the cross coupling copolymerization of two carbazole derivative monomers and a acridine derivative TADF monomer(ABTPy)containing terpyridine group,and managing the TADF monomer feed molar ratio of 1%,5%,10%and 50%.The polymers with low content of TADF unit show dual emissions peaked at 420 and 488 nm in dilute solution,whereas all polymers only display a single emissive peak ranging from 470 nm to 508 nm in neat film.Their TADF features are confirmed by the transient photoluminescence decay spectra,in which a short-lifetime prompt component(12‒15 ns)and a long-lifetime delayed component(1.3‒4.8μs)are clearly detected.The non-doped and solution-processed organic light-emitting diodes(OLEDs)using the polymer neat films as emissive layers all show blue emissions with emissive wavelength from 452 nm to 484 nm.The OLED based on PCZABTPy10 achieves excellent performances with the maximum external quantum efficiency(EQE)of up to 9.4%and the low turn-on voltage of 3.0 V.Moreover,the EQE still remains 7.4%at the luminance of 1000 cd/m^(2).
作者
邓浩
姚兵
窦昆昆
宋彦尧
秦川江
战宏梅
程延祥
Hao Deng;Bing Yao;Kun-kun Dou;Yan-yao Song;Chuan-jiang Qin;Hong-mei Zhan;Yan-xiang Cheng(State Key Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022;School of Applied Chemistry and Engineering,University of Science and Technology of China,Hefei 230026)
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2023年第2期217-224,共8页
Acta Polymerica Sinica
基金
国家自然科学基金(基金号51973210,22171257)资助项目.
关键词
热诱导延迟荧光
共轭聚合物
三联吡啶
蓝光
电致发光
Thermally activated delayed fluorescence
Conjugated polymer
Terpyridine
Blue emission
Electroluminescence
