Effects of exciton diffusion length on the Flexible White Organic Light Emitting Diodes

A flexible white OLED has been fabricated in this study. A red dye, DCJT, was doped at different position in the blue host emissive layer, ADS082. From the relationship between red spectrum intensity and red-dye doped position, the effective diffusion region for excitons can be obtained. In this study's structures, the effective diffusion region for excitons is found to he within the 15 nm rang from the NPB/AD082 interface, Furthermore, for obtaining a pure white OLED, a green dye, C6, was also doped in the blue emissive layer, following DCJT-doped layer, to enhance the green spectrum intensity. The white OLED having CIE coordinates of (0.34, 0.34) can be obtained. The maximum brightness is about 2000 cd/m2 at 50 mA and luminance yield > 6 cd/A.