The influence of the Rubrene thickness on the performance of white organic light-emitting devices

Abstract

A group of white OLEDs (organic light-emitting devices), were fabricated using the blue yellow complementary principle. Among them, MCP(1,3-Bis(carbazol-9-yl)benzene) was used as the main material for the blue light layer, FIrPic(Bis(3,5-difluoro)-2-(2-pyridyl)phenyl-(2-carboxypyridyl)iridium(III)) as the phosphorescent object material, and Rubrene(5,6,11,12-Tetraphenylnaphthacene) as the fluorescent material for the yellow light layer. The device structure is NPB(N,N′-Bis(naphthalen-1-yl)-N,N′-bis(phenyl)-benzidine) (20 nm)/Rubrene (0.5 nm)/MCP (3 nm)/MCP: FIrPic (30 nm, 10%)/Rubrene (z nm)/TPBi(1,3,5-Tris(1-phenyl-1Hbenzimidazol-2-yl) benzene)(10 nm)/Alq3(20 nm/LiF (0.6 nm)/Al (100 nm). By adjusting the thickness of Rubrene, the structure of the device was optimized and the performance of the device was improved. When the thickness of Rubrene was 0.5 nm, the performance of the device was the best, the maximum efficiency was 6.41 cd/A, the maximum luminance was 8344 cd/m2. When the driving voltage changed from 5 V to 14 V, the device changed from warm white light to cold white light.