基于茚并咔唑与均三嗪的N型主体材料的合成及其在绿色磷光器件中的性能研究

Synthesis of N-type host materials based on indocarbazole and s-triazine and properties in green phosphorescent devices

为了获得低驱动电压、长寿命和高光效的有机电致发光二极管(OLED),本文介绍了一系列基于1,3,5-三嗪和7,7-二甲基-5,7-二氢茚并[2,1-b]咔唑的新型n型磷光主体材料DTRz、DBTRz和DCNTRz。首先,对它们的电化学性质、光物理性能及热稳定性进行研究,并进行密度泛函理论(DFT)计算。实验与计算分析结果表明:DTRz、DBTRz和DCNTRz具有较高的三线态能级(2.83,2.71,2.72 eV),较高的分解温度(411,499,419oC),随后与P型主体NBPBC(1∶1)混合后对其光致发光光谱进行研究,并以此为基础,以Pt(BBP)为客体掺杂剂进行了器件制备。器件结果分析表明,DCNTRz∶NBPBC为基础的器件的启动电压为2.1 V,最高外量子效率达14.3%,最大亮度达221589 cd·m^(-2),在1000 cd·m^(-2)下电流效率最高达46.5 cd·A^(-1),最大功率效率达45.7 lm·W^(-1)。特别是在4000 cd·m^(-2)下器件寿命(LT95)达282 h,比以DTRz∶NBPBC为基础的器件的寿命提高了54%,实现了同时具备低启动电压、高寿命和高光效等优越性能的绿光OLED。

In order to obtain organic electroluminescent diodes(OLEDs)with low driving voltage,long lifetime and high light efficiency,a series of novel n-type host materials DTRz,DBTRz and DCNTRz based on1,3,5-triazine and 7,7-dimethyl-5,7-dihydroindolinazol[2,1-b]carbazole are introduced in this paper.First,their electrochemical properties,photophysical properties and thermal stability were studied,and DFT calculations were performed.The experimental and computational analysis results show that DTRz,DBTRz and DCNTRz have higher triplet energy levels(2.83,2.71,2.72 eV),higher decomposition temperatures(411,499,419oC).Then,the photoluminescence spectrum was studied after mixing with P-type host NBPBC(1∶1),and based on this,the device was fabricated with Pt(BBP)as the guest dopant.The analysis of the device results shows that the DCNTRz∶NBPBC-based device has a turn-on voltage of 2.1 V,a maximum external quantum efficiency of 14.3%,a maximum brightness of 221589 cd·m^(-2),a current efficiency of 46.5cd·A-1at 1000 cd·m^(-2),and a maximum power efficiency of 45.7 lm·W^(-1).In particular,the device lifetime(LT95)reaches 282 h at 4000 cd·m^(-2).54%higher lifetime than DTRz∶NBPBC-based devices.A green OLED with excellent performance such as low turn-on voltage,high lifetime and high luminous efficiency is realized.