| Summary: | 碩士 === 國立交通大學 === 應用化學系所 === 93 === In this thesis, highly stable organic light emitting devices was made by using a uniformly mixed hole transport layer (UM-HTL) composed of a mixture of 2-methyl-9,10-di(2-naphthyl)anthracene (MADN) and N,N’-bis(1-naphthyl)-N,N’-diphenyl,1,1’-biphenyl-4,4’-diamine (NPB) in a 3:7 (MADN:NPB) ratio. In 10-(2-benzothiazolyl)-1,1,7,7-tetramethyl- 2,3,6,7-tetrahydro-1H,5H,11H-benzo[l]-pyrano[6,7,8-ij]quinolizin-11-one (C-545T) doped green device, the stability of device with a UM-HTL can be greatly improved to 3 times (initial luminance normalized to 100 nits, 52200 hrs) longer than that of the conventional NPB based HTL without deteriorating on its driving voltage, current efficiency and emissive color significantly. This improvement in stability can be attributed to the fact that the accumulations of positive charge in emission layer have been effectively suppressed. Moreover, using UM-HTL in MADN based blue device systems, the stability of device also can be greatly improved to at least 1.5 times longer than that of the conventional NPB based HTL without deteriorating on its driving voltage, current efficiency and emissive color significantly. These results indicated that UM-HTL can improve the stability of device with any kind of emission color without affecting its emission property. Furthermore, UM-HTL has good thin film thermal property to solve the issue of low Tg in conventional HTL materials. Hence, this made UM-HTL a potential candidate to replace the conventional HTL for each emission color.
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