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...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.展开更多
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)+5 种基金the Suzhou Science and Technology Plan Project (SYG202010)supported by Suzhou Key Laboratory of Functional Nano & Soft MaterialsCollaborative Innovation Center of Suzhou Nano Science & Technologythe 111 ProjectJoint International Research Laboratory of Carbon-Based Functional Materials and Devices。
文摘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.
