π-Stacked host materials based on spirofluorene scaffolds for warm white OLEDs achieving 94.7 lm W^(-1) at 1,000 cd m^(-2)  

作　　者：Yuan-Lan Zhang Sheng-Yi Yang Zi-Qi Feng Yang-Kun Qu Dong-Ying Zhou Cheng Zhong Liang-Sheng Liao Zuo-Quan Jiang 

机构地区：[1]Jiangsu Key Laboratory for Carbon-Based Functional Materials&Devices,Soochow University,Suzhou 215123,China [2]Institute of Functional Nano&Soft Materials(FUNSOM),Soochow University,Suzhou 215123,China [3]Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials,Hubei Key Lab on Organic and Polymeric Optoelectronic Materials,Department of Chemistry,Wuhan University,Macao 999078,China [4]Macao Institute of Materials Science and Engineering,Macao University of Science and Technology,Wuhan 430072,China

出　　处：《Science China Chemistry》2022年第11期2219-2230,共12页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China (51873139, 61961160731, 62175171, 22175124);the Natural Science Foundation of Jiangsu Province of China (BK20220057);the Suzhou Science and Technology Plan Project (SYG202010);supported by Suzhou Key Laboratory of Functional Nano & Soft Materials;Collaborative Innovation Center of Suzhou Nano Science & Technology;the 111 Project;Joint International Research Laboratory of Carbon-Based Functional Materials and Devices;。

摘　　要：Power efficiency(PE)at high brightness is considered as the rigorous standard of high-quality white organic light-emitting diodes(WOLEDs),for which the host material plays a significant role in energy conservation for practical lighting applications.Herein,PE is successfully enhanced to a new level through the method ofπ-stacked host molecular with spirofluorene scaffold.We design host materials by confining two donor units in a very short distance to enlarge theπ-electron spatial delocalization for facilitating the hole hopping process and engaging a rigid donor as the space-lock to suppress the quenching effect as well as induce host bipolar property.Based on this unique molecular design,the red,green,and blue(RGB)monochromic organic lightemitting diodes(OLEDs)demonstrate high external quantum efficiencies(EQEs)of 28.4%,26.0%,and 31.2%with ultralow roll-off,respectively.More encouragingly,the warm WOLEDs achieve record-high current efficiency(CE)of 109.5 cd A^(-1),PE of 109.1 lm W^(-1),and EQE of 32.9%.Even under operating brightness of 1,000 cd m^(-2),the devices can still realize 94.7 lm W^(-1)of PE,which represents the highest applicable PE value in the reported WOLEDs and for the first time single-host based WOLEDs with a performance exceeding that of a conventional fluorescent tube(70 lm W^(-1))without any light-extraction technique.

关 键 词：white organic light-emitting diodes power efficiency universal host single-EML 

分 类 号：TB34[一般工业技术—材料科学与工程] TN383.1[电子电信—物理电子学]