Fluorene pendant-functionalization of poly(N-vinylcarbazole)as deep-blue fluorescent and host materials for polymer light-emitting diodes  

作　　者：Ning Sun Qin Zou Wenyu Chen Yingying Zheng Kai Sun Chunbin Li Yamin Han Lubing Bai Chuanxin Wei Jinyi Lin Chengrong Yin Jianguo Wang Wei Huang 

机构地区：[1]Key Laboratory of Flexible Electronics(KLOFE)and Institute of Advanced Materials(IAM),Nanjing Tech University(NanjingTech),Nanjing 211816,China [2]College of Chemistry and Chemical Engineering,Inner Mongolia Key Laboratory of Fine Organic Synthesis,Inner Mongolia University,Hohhot 010021,China [3]Centre for Molecular Systems and Organic Devices(CMSOD),Key Laboratory for Organic Electronics and Information Displays and Institute of Advanced Materials(IAM),Nanjing University of Posts and Telecommunications,Nanjing 210023,China [4]Shaanxi Institute of Flexible Electronics(SIFE),Northwestern Polytechnical University(NPU),Xi’an 710072,China

出　　处：《Chinese Chemical Letters》2023年第8期484-489,共6页中国化学快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.22105099 and 61874053);Natural Science Foundation of Jiangsu Province(No.BK20200700);the China Postdoctoral Science Foundation(No.2022M711591);the open research fund from Anhui Province Key Laboratory of Optoelectronic Materials Science and Technology(No.OMST202101);the State Key Laboratory of Luminescent Materials and Devices(South China University of Technology).

摘　　要：π-Electron coupling of pendant conjugated segment inπ-stacked semiconducting polymers always causes the formation of defect trapped sites and further quenched high-band excitons,which is harmful to the performance and stability of deep-blue polymer light-emitting diodes(PLEDs).Herein,considerate of“defect”carbazole(Cz)electromers in poly(N-vinylcarbazole)(PVK),a series of fluorene units are introduced into pendant segments(PVCz-DMeF,PVCz-FMeNPh and PVCz-DFMeNPh)to suppress the strongπ-electron coupling of pendant Cz units and enhance radiative transition toward fabricating sable PLEDs.Compared to PVCz-FMeNPh and PVCz-DFMeNPh,PVCz-DMeF spin-coated films show a relatively efficient deep-blue emission,completely similar to its single pendant chromophore,confirmed an extremely weak charge-transfer and electron coupling between adjacent pendant segments.Therefore,PLEDs based on PVCz-DMeF present stable and deep-blue emission with a high color purity(0.17,0.08),associated with extremely weak defect emission at 600∼700nm(induced by carbazole electromers).Finally,PLEDs based on PVCz-DMeF/F8BT blended films(1:1)also present the high maximum luminance(Lmax)of 6261 cd/m2 and current efficiency(CE_(max))of 2.03 cd/A,confirmed slightly trapped sites formation.Therefore,precisely control the arrangement and packing model of pendant units inπ-stacked polymer is an essential prerequisite for building efficient and stable emitter for optoelectronic devices.

关 键 词：Poly(N-vinylcarbazole) FLUORENE Deep-blue emission Energy transfer Polymer light-emitting diodes 

分 类 号：TQ317[化学工程—高聚物工业] TN312.8[电子电信—物理电子学]