Side-by-side Patterned RGB Domain Color Device to Optimize Full Color OLED

摘要

Side-by-side patterned RGB domain color device of organic light emitting diode(OLED) with structure of ITO/TPD/EML/Alq_3/Al:Li(0.1% wt) was fabricated under high vacuum of 2 X 10~(-6) torr. Total active area of device is 44 X 25 mm~2 and it has 400 X 440 μm~2 of pixel pitch. Each of emitting layer (EML) for RGB -was formed using Alq_3 doped with 4-(dicyano-methylene)-2-methyl-6-(p-dimethylaminostryl)-4H-pyran(DCM), Alq_3 and l,2,3,4,5-pentaphenyl-l,3-cyclopenta-diene(PPCP) respectively. Luminescent efficiency, color purity and brightness were observed in the various conditions of emitting layer, film thickness and doping ratio to optimize the best performance for full color OLED. Optical characteristics of these RGB devices were compared with those of Alq_3 doped with 4-(dicyanomethylene)-2-methyl-6-(julolidin-4-yl-vinyl)-4H-pyran(DCJTB) for red emission, Alq_3 doped with 10-(2-benzo-thiazolyl)-2,3,6,7-tetrahydro-l,l,7,7-tetramet}ryl-1H,5H, 11H-(l)benzopyrano(6,7,8-ij)-quinolizin-ll-one(C545T) for green emission and 1,4-bis(2,2-diphenylvinyl) biphenyl(DPVBi) for blue emission. Introduction of 4,4',4"-tris(N-3-methylphenyl-N-phenyl-amino)-triphenyl- amine(m-MTDATA) as hole injection layer(HIL) can lower the approximately 40% of threshold voltage in the green device with the structure of ITO/m-MTDATA/TPD/Alq/Al:Li(0.1% wt) as well as improve luminescent efficiency.