文献类型：期刊文献

英文题名：The Effect of Carrier Transport Layer on the Electroluminescent Properties of Solution-Processed Thermally Activated Delayed Fluorescent Device based on 4CzPN

作者：Zhang, Lijiang[1];Lu, Zhaoyue[1];Wang, Junling[2]

机构：[1]East China Univ Sci & Technol, Sch Phys, Shanghai 200237, Peoples R China;[2]Army Acad Armored Forces, Basic Dept, Beijing 100072, Peoples R China

年份：2022

卷号：259

期号：10

外文期刊名：PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS

收录：;EI(收录号：20222112153273);WOS:【SCI-EXPANDED(收录号:WOS:000799537600001)】；

基金：The authors acknowledge the financial support from the National Natural Science Foundation of China (11504109).

语种：英文

外文关键词：carrier balance; solution-processed; thermally activated delayed fluorescence; triplet-charge annihilation

摘要：The performance of solution-processed organic light-emitting diodes (OLEDs) based on thermally activated delayed fluorescent (TADF) emitter of 3,4,5,6-tetrakis (carbazol-9-yl)-1, 2-dicyanobenzene (4CzPN) is optimized via adjusting the carrier transport layer. The device with 1,3,5-Tris(1-phenyl-1Hbenzimidazol-2-yl) benzene (TPBi) as electron transport layer (ETL) demonstrates much higher efficiency compared to the device with 1, 3, 5-Tri [(3-pyridyl)-phen-3-yl] benzene (TmPyPB) as ETL. The proposed mechanism is that triplet-charge annihilation is alleviated since fewer holes are accumulated at the interface between the emission layer (EML) and ETL due to lower lying highest occupied molecular orbital (HOMO) of TPBi. In addition, the hole transport material of (N,N '-bis (3-methylphenyl)-N,N '-bis (phenyl)-benzidine) (TPD) inserted at the PEDOT:PSS/EML interface could block electron leakage and suppress the exciton quenching by PEDOT:PSS. And thus, the device efficiency is improved. The current efficiency of 18.46 cd A(-1) and external quantum efficiency of 5.99% are achieved for the solution-processed 4CzPN-based device with TPBi as ETL and TPD as hole transport layer (HTL). It is illuminated that suppressing exciton quenching via manipulating carrier behaviors in the EML is an efficient approach for fulfilling high-performance solution-processed TADF devices.