DPVBi空穴阻挡层对OLED性能的优化

摘要

High performance organic light emitting devices ( OLEDs) should have a low operating voltage, high efficiency and relatively good stability. Inserting of a hole blocking layer (HBL) between hole transporting layer ( HTL) and electron transporting layer ( ETL) is one of the effective method to improve device performances. In this paper, a DPVBi HBL was incorporated in OLED between the PEDOT: PSS hole injection layer (HIL) and Alq3 ETL. Such a structure helps to reduce the hole-leakage of the cathode, which resulting an enhanced device performances. The optimized device with a thickness of 30 nm DPVBi HBL shows a significantly improved current efficiency (5.2 cd/A) and luminance (24 350 cd/m2 ) , which is 20% and 87% higher compared with those data of reference device with the structure of ITO/PEDOT: PSS/NPB/Alq3/ LiF/Al.%研究了宽带隙有机小分子材料DPVBi作为空穴阻挡层对OLED器件效率和亮度的优化作用.DPVBi的引入有效地改善了以PEDOT:PSS做空穴注入层的OLED器件的空穴过剩问题.实验结果表明:通过优化DPVBi的厚度,插入30 nm厚的DPVBi空穴阻拦层可以有效地平衡OLED器件的电子和空穴浓度,降低器件的工作电压,优化器件的各项性能.该器件的效率和亮度分别是器件结构为ITO/PEDOT:PSS/NPB/Alq3/LiF/A1参比器件的1.2倍和1.87倍.