通过具有高表面能和延长共轭链段的耐溶剂空穴传输材料实现高效喷墨打印QLED  

High-efficiency inkjet-printed quantum-dot light-emitting diode enabled by solvent-resistant hole transport materials with high surface energy and extended conjugation

作　　者：邱庚锐 易袁秋强 谢黎明 苏富燕 王婷 苏文明 崔铮 Gengrui Qiu;Yuan-Qiu-Qiang Yi;Liming Xie;Fuyan Su;Ting Wang;Wenming Su;Zheng Cui(Printable Electronics Research Center,Nano Devices and Materials Division,Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences,Suzhou 215123,China;Nano Science&Technology Institute,University of Science and Technology of China,Suzhou 215123,China;pi-Conjugated Polymers Unit,Okinawa Institute of Science and Technology,1919-1 Tancha,Onna-son,Kunigami-gun,Okinawa 904-0495,Japan)

机构地区：[1]Printable Electronics Research Center,Nano Devices and Materials Division,Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences,Suzhou 215123,China [2]Nano Science&Technology Institute,University of Science and Technology of China,Suzhou 215123,China [3]pi-Conjugated Polymers Unit,Okinawa Institute of Science and Technology,1919-1 Tancha,Onna-son,Kunigami-gun,Okinawa 904-0495,Japan

出　　处：《Science China Materials》2024年第1期205-213,共9页中国科学（材料科学）（英文版）

基　　金：financially supported by the National Key Research and Development Program of China (2022YFB3606500);the Natural Science Foundation of Jiangsu Province (BK20210125)。

摘　　要：量子点发光二极管(QLED)溶液法制备的特点和喷墨打印高度契合,在印刷显示器领域展现出巨大的应用潜力.制作QLED器件时,下层薄膜的表面能对上层薄膜的铺展起着至关重要的作用,高表面能可以促进不同功能膜层之间的紧密接触并减少漏电流.然而,已报道的交联空穴传输材料(HTM)低的表面能不利于喷墨打印.在此,我们通过分子设计开发了一种可交联HTM及其聚合物,新的聚合物命名为[9-(4-(乙氧基甲基)苯基)-3-(7-(9-(4-(己炔基)乙氧基甲基)苯基)-9H-咔唑-3-基)-9H-芴]-9H-咔唑(PDA-FLCZ),由3,3′-(9,9-二甲基-9H-芴-2,7-二基)双[9-(4-(丙-2-炔-1-氧基)甲基)苯基]-9H-咔唑(DA-FLCZ)聚合得到.这种新型HTM采用原位光热交联和预聚后热交联两种交联策略,都可以在较低的交联温度下形成稳定的网络结构,具有优异的耐溶剂性和较高的表面能.通过优化交联工艺,交联PDA-FLCZ薄膜实现了更高的空穴迁移率和更低的陷阱密度,其对应的旋涂QLED器件的最大外量子效率(EQE)达到17.59%,比基于DA-FLCZ的器件(14.25%)高出23%.此外,基于交联PDA-FLCZ的喷墨打印QLED显示出15.28%的最大EQE,接近其旋涂器件值的90%.Quantum-dot light-emitting diodes(QLEDs)prepared using the solution method have great potential in printed displays,particularly when combined with inkjet printing.The surface energy of the lower film plays a crucial role in the spreading of the upper film in QLEDs.High surface energy promotes close contact between different functional film layers and reduces leakage currents.However,cross-linkable hole transport materials(HTMs)with low surface energies are unsuitable for inkjet printing.Herein,a cross-linkable HTM and its polymer derivative were fabricated using a molecular design.The new polymer poly 9-(4-(ethox-ymethyl)phenyl)-3-(7-(9-(4-((hexa-2,4-diyn-1-yloxy)methyl)-phenyl)-9H-carbazol-3-yl)-9,9-dimethyl-9H-fluoren-2-yl)-9H-carbazole(PDA-FLCZ)is synthesized via the polymerization of 3,3′-(9,9-dimethyl-9H-fluorene-2,7-diyl)bis[9-(4-(prop-2-yn-1-yloxy)methyl)phenyl]-9H-carbazole(DA-FLCZ).For the new HTM,stable network structures can be formed at low cross-linking temperatures using two cross-linking strategies,in-situ photothermal cross-linking and thermal cross-linking after prepolymerization,exhibiting excellent solvent re-sistance and high surface energy.By optimizing the cross-linking process,the cross-linked PDA-FLCZ achieves higher hole mobility and lower trap density,resulting in a maximum external quantum efficiency(EQE)of 17.59%for spin-coated QLEDs,which is 23%higher than that of the device based on DA-FLCZ(14.25%).Moreover,the inkjet-printed QLEDs based on the cross-linked PDA-FLCZ demonstrate a max-imum EQE of 15.28%,which is close to 90%of the value of its spin-coated devices.

关 键 词：空穴传输材料 量子点发光二极管 喷墨打印 空穴迁移率 耐溶剂性 交联工艺 热交联 溶液法 

分 类 号：TN312.8[电子电信—物理电子学]