High efficiency blue organic light emitting devices doped by BCzVBi in hole and electron transport layer

The electroluminescent characteristics of blue organic light-emitting diodes(BOLEDs) were fabricated with single emitting layer using host-dopant system and doped charge carrier transport layers. The structure of the high efficiency BOLED device was; NPB(600A˚)/NPB:BCzVBi-7%(100A˚)/ADN:BCzVBi-7%(300A˚)/BAlq:BCzVBi-7%(100A˚)/BAlq(200A˚)/Liq(20A˚)/Al(1200A˚) to optimize probability of exciton generation by doping BCzVBi in emitting layer and hole/electron transport layers(HTL/ETL) as well. Luminance and luminous efficiency of BOLED doped BCzVBi in EML and HTL/ETL improved from 10090 cd/m2 at 9.5V and 6.44 cd/A at 4.0V to 13190 cd/m2 at 9.5V and 7.64 cd/A at 4.0V about 30% and 18%, respectively, with CIE coordinates of (0.14, 0.17) comparing to BOLED doped BCzVBi in EML only.