高效蓝色有机发光材料与器件

Organic electroluminescent materials and devices

有机半导体由于具有柔软性而可卷曲成形,具有可溶加工性而采用印刷成膜,从而使得加工成本有可能大大降低而受到广泛关注.本文针对有机发光材料中n型材料不足及宽能带与高电子传输性不可同时实现的难题,我们设计与合成了一系列的宽带电子传输材料并应用于蓝色磷光器件,实现了将近100%的内量子效率蓝色磷光.针对蓝色发光材料色度不纯的问题,我们设计了深蓝色荧光材料,其器件色度坐标CIE(0.15,0.08),与NTSC标准蓝光相当接近,同时实现接近理论极限的外量子效率发光.针对器件中由于平面波导及表面等离激元等能量模式的损失,我们利用有机材料的自团聚现象在有机发光器件金属阴极上制备无规的纳米结构,把束缚能量转化成自由光子,使得顶出光效率提高到2.1–2.7倍,且不改变原有器件的发光光谱形状.

The organic semiconductor has been paid for widespread concerns because it can be curled to form a film due to its flexibility and printability resulting from its high solubility in solvents, therefore the processing cost may be greatly reduced. Considering the poorness of effective electron transport materials and the dilemma of wide energy gap with high electron mobility for organic molecules, we have synthesized a series of electron transport materials for blue phosphorescent devices, nearly 100% internal quantum efficiencies has been achieved. Considering the impure chromaticity for blue light, we have designed a deep blue fluorescent material to give an emission for the device at CIE （0.15, 0.08）, quite close to the NTSC standard blue, and a theoretical limit of the external quantum efficiency of the device has been obtained. Due to the energy loss resulting from the planar waveguide and surface plasmon mode in the device, random nanostructures have been fabricated on the metal cathode of organic light-emitting device through a self aggregation of organic materials, to convert the binding energy into free photons. The light extraction efficiency has been increased to 2.1-2.7 times higher, however, without changing the spectral shape of the device.