Effect of TCTA Layer on Exciton Positions of Red and Green Phosphorescent Organic Light Emitting Diodes

Red and green phosphorescent organic light emitting diodes were fabricated,utilizing GIr1 and R-4B(novel red and green) phosphorescent materials.Device structure was ITO/MoO3(50 nm)/NPB(40 nm)/TCTA(10 nm)/CBP∶14%GIr1(30 nm)/TCTA(x)/CBP∶2%R-4B(10 nm)/BCP(10 nm)/Alq3(40 nm)/LiF(1 nm)/ Al(100 nm).The luminescent properties were studied by inserting different thickness of TCTA(regulation of carrier) spacer layer between red and green emitting layer to adjust the distribution of carriers and excitons.The results showed that the optimum performance of OLED was achieved when the thickness of TCTA spacer layer is 1 nm.The maximum the device performance reached 13.72 cd/A,0.509 mA/cm2 and 69.91 cd/m2 at 6 V.While for 0 nm(none spacer),the device performance reached 11.67 cd/A,1.848 mA/cm2 and 215.7 cd/m2 at 6 V.