发光层厚度对联苯乙烯衍生物蓝色有机发光器件性能的影响

本文制备了联苯乙烯衍生物(4, 4'-bis(2, 2'-diphenylvinyl)-1, 1'-biphenyl, DPVBi) 为发光层的蓝色有机电致发光器件. 器件性能随发光层厚度变化而变. 在DPVBi厚度为10---50 nm范围内, 同样电流密度下器件亮度及效率随DPVBi厚度增加先增后减, 40 nm时最佳, 最高亮度达到15840 cd/m², 最高外量子效率达到3.2%, 器件色坐标(Commission Internationale de l'Eclairage (CIE) co-ordinates) 为(0.15, 0.15). DPVBi厚度超过40 nm时器件发光光谱出现红移而致色度变差, 其原因可归于微腔效应所致. 同时, 通过实验结果分析表明DPVBi中激子扩散长度位于20---30 nm范围.

Influence of active layer thickness on the performance of distyrylarylene derivative blue organic light-emitting device

Thickness of emissive layer in organic electroluminescent device is one of the important factors affecting the device performance. In this report, a blue electroluminescent device with an active layer of 4, 4'-bis(2, 2'-diphenylvinyl) -1, 1'- biphenyl (DPVBi) is fabricated. The device performance varies with the thickness of DPVBi. With the increase of the DPVBi thickness between 10---50 nm, the device luminance and efficiency at the same current density first increase and then decrease, the device with a DPVBi thickness of 40 nm exhibits the highest luminance of 15840 cd/m² and a maximum external quantum efficiency of 3.2%, with Commission Internationale de l'Eclairage (CIE) co-ordinates being (0.15, 0.15). The luminescent spectral red shift and the color purity deteriorate when the thickness is over 40 nm, which can be attributed to a result of microcavity effect. In the meantime, the analysis from experimental results shows that the exciton diffusion length in DPVBi is between 20---30 nm.