Abstract:

The saturated red polymer electrophosphorescent devices have been fabricated. With the device structures of ITO/PEDOT∶PSS/PVK/PFO+30%PBD∶TDPPPt/Ca/Al(ITO:indium tin oxide, PEDOT: poly(3,4-ethylenedioxythiophene), PSS:poly(styrenesulfonate), PVK:poly-N-vinyl carbazole), based on short lifetime meso-tetrakis(4-n-decanoyl-phenyl) porphyrin platinum(Ⅱ) complex(TDPPPt) and poly(2,7-9,9-dioctylfluorene)(PFO) in which 30% 2-(bi-phenyl-4-yl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole(PBD) was doped. The saturated red emission is obtained when doping concentration of TDPPPt is 3%~10%. The CIE(Commission Internationale de L′Eclairage) coordinates of the device is about at (0.66, 0.28) and unchangeable when driven voltage increases from 7 V to 14 V. The maximum luminance and luminance efficiency(ηl) is 1.390 cd/m2 at 18 V and 1.34 cd/A at 18×10-3 A/cm2, respectively. Furthermore, the devices show excellent stability under high driven current density. ηl only drops to 88% and 73% of maximum efficiency at 100×10-3 A/cm2, and 150×10-3 A/cm2, respectively. We tentatively attribute excellent devices stability under high driven current density to the short radiative lifetime that avoids triplet-triple annihilation.

Key words: meso-tetrakis (4-n-decanoyl-phenyl) porphyrin platinum(Ⅱ), Polymer Electrophosphorescent Devices, lifetime of phosphorscence