Color optimization of red OLEDs via periodic and gradient deposition rate of fluorescent dopants

摘要

We have investigated a method to enhance the light emission efficiency and color tuning for mixture of dyes with varying the growth parameters, during Alq(3):Nile Red deposition. We used solvent bath and green laser (532 nm) for improvement of the performance of devices. This paper presents two kind of evaporation method, periodic and gradient. We observed that periodic emission layers can greatly improve the device performances such as electroluminescence, chromaticity coordinates, luminance, and reduced the turn on voltage. The periodic 3 structure with evaporation rate of (0.1 - 3 - 2 - 3 - 2 - 0.1 A degrees/s) has a luminance of 3000 cd/m(2) and maximum efficiency of 1.8 cd/A at 18 V which are the highest values among devices.