Thermally cross-linkable hole-transport materials enable solution-processed blue OLED with LT95 over 150 h  

基于热交联空穴传输材料的溶液法蓝光OLED器件LT_(95)寿命超过150小时

作　　者：Xinkang Zhang Hao Yan Xiaopeng Zhang Hong Meng 张鑫康;严浩;张小鹏;孟鸿(School of Advanced Materials,Peking University Shenzhen Graduate School,Shenzhen,518055,China)

机构地区：[1]School of Advanced Materials,Peking University Shenzhen Graduate School,Shenzhen,518055,China

出　　处：《Science China Materials》2024年第9期2767-2777,共11页中国科学（材料科学）（英文版）

基　　金：supported by the National Natural Science Foundation of China(22275003);Shenzhen Fundamental Research Program(JCYJ20200109140425347);the Development and Reform Commission of Shenzhen Municipality(XMHT20200106002);the Key-Area Research and Development Program of Guangdong Province(2019B010924003);Guangdong Basic and Applied Basic Research Foundation(2020B1515120030);provided by Guangdong Key Laboratory of Flexible Optoelectronic Materials and Devices;Guangdong International Science and Technology Cooperation Base of Optoelectronic Materials and Device Technology。

摘　　要：The solution-processed method for organic light-emitting diodes(OLEDs)offers the benefits of cost-effectiveness and enhanced material utilization.In the multilayer architecture of solution-processed OLEDs(SOLEDs),the role of hole-transport materials(HTMs)is pivotal for cascade hole injection.However,commercial HTMs such as poly-(9,9-dioctylfluorene-alt-N-(4-sec-butylphenyl)-diphenylamine)(TFB)are hampered by incompatible energy levels and redissolution with overlayer solvent,prompting the exploration of cross-linkable HTMs(X-HTMs)for better performance.In this study,we have developed two novel small-molecule X-HTMs,N^(1),N^(1)′-((perfluoropropane-2,2-diyl)bis(4,1-phenylene))bis(N^(4),N^(4)-diphenyl-N^(1)-(4-vinylphenyl)benzene-1,4-diamine)(FTPA-V)and N,N′-((perfluoropropane-2,2-diyl)bis-(4,1-phenylene))bis(9-phenyl-N-(4-vinylphenyl)-9H-carbazol-3-amine)(FPCz-V),which incorporate thermally cross-linkable vinyl groups and electron-rich trifluoromethyl units.The X-HTMs enhance interfacial contact through superior film formation and solvent resistance,along with optimal energy levels.The application of X-HTMs significantly enhances the efficiencies and longevities of blue,green,and red SOLEDs.Specially,blue SOLED incorporating FPCz-V exhibits unprecedented lifetime(LT95)extending to over 150 h,setting a new record for blue SOLEDs.The electrochemistry stability,high bond dissociation energy,and triplet energy levels of X-HTMs can effectively minimize exciton annihilation and prolong the lifetime.These findings underscore the potential of X-HTM optimization to propel the development of stable solution-processed luminescent technologies.溶液法在有机发光二极管(OLED)的制备工艺中具有成本低和材料利用率高的优势.在溶液加工有机发光二极管(SOLED)的多层架构中,空穴传输层所用材料(HTM)对于级联空穴注入至关重要.然而,常用的商业HTM材料TFB由于能级不匹配和上层溶剂再溶解问题而使器件性能受限,因此需要可交联的HTM(X-HTM)以获得更好的器件性能.在本研究中,我们设计合成了两种新型小分子X-HTMs,FTPA-V和FPCz-V,这两种材料中均引入了热交联的乙烯基团和吸电性三氟甲基基团.所合成的X-HTMs具有优异的膜形貌和溶剂抗性,优化了界面接触.使用X-HTMs显著提高了蓝绿红光SOLEDs的效率和寿命.特别是采用FPCz-V的蓝光SOLED显示出超过150小时的寿命(LT95),是蓝光SOLED寿命的新记录.X-HTMs的电化学稳定性、高键解能和高三线态能级能有效地减少激子湮灭并延长寿命.这些发现体现了交联HTM材料的潜力,推动了稳定的溶液加工发光技术的发展.

关 键 词：solution-processed OLED cross-linkable HTMs solvent resistance bond dissociation energy exciton-polaron annihilation 

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]