采用复合空穴注入层提高有机电致发光器件的性能

Improved Performance of Organic Light Emitting Diodes Using Combined Hole-injecting Layer

制备了以Ag/SAM/m-MTDATA为复合空穴注入层的NPB/Alq3双层异质结发光器件,研究了器件的性能并与传统的器件进行了对比。考察了银膜厚度的变化对器件性能的影响。研究了光谱窄化以及微腔效应对器件的影响。研究结果表明:在ITO表面制备4-FTP自组装单分子膜修饰的5 nm厚的金属银膜,可以在保持阳极透明性的基础上,增强空穴的注入,改善界面的形貌,进而提高器件性能。制备的ITO/Ag/SAM/m-MTDATA/NPB/Alq3/LiF/Al器件的启亮电压为4 V,最大电流效率为6.9 cd/A,最大亮度为34 680 cd/m2(12 V);优于以ITO为阳极的对比器件(25 300 cd/m2@12 V)。

A double layer NPB/Alq3 heterojunction organic light emitting device using Ag/4-FTP （SAM）/m-MTDATA as combined hole-injecting layer was fabricated. The device performance was studied and compared with the control device. The effect of the Ag layer thickness on the device per- formanee is also investigated. The variation of the spectral narrowing and intensity enhancement can be explained with microcavity effects. The results revealed that indium tin oxide （ITO） anode modi- fied with Ag（5 nm）/4-FTP（SAM） demonstrated good transparency, enhanced hole injection ability and smooth interface morphology, which result in an improved device performance. The highest lu- minance of 34 680 cd/m^2 at 12 V and a luminous efficiency of 6.9 cd/A were achieved for the de- vice with the structure of ITO/Ag/4-FTP （SAM）/m-MTDATA/NPB/Alq3/LiF/A1. However, the control device showed 25 300 cd/m^2 at the same bias.