Effects of Doping Concentration on the Performance of Blue Fluorescent OLEDs

The OLEDs were fabricated with the structure of ITO/m-MTDATA(20nm)/NPB(10nm)/ DPVBi:BCzVBi(15 nm,x%)/TPBi(10 nm)/Alq3(20nm)/Cs2CO3：Ag2O(2nm,20%)/ Al (100 nm) by using the method of fluorescent dyes dopant. The effect of different DPVBi:BCzVBi doping concentration(x=5,8, 10 and 15) on the properties of blue light device was studied．Results show that when the mass fraction of fluorescent dye BCzVBi was 10%, performances of the device were the best. This device had a maximum current efficiency of 4.19 cd /A and maximum luminance of 14757 cd /m2 at 17 V.When the driving voltage changed from 8 to 17 V, the efficiency of the devices had been rising. There are not the phenomenon of efficient roll-off.