Carriers Confinement for Polymer Electroluminescent Devices with Multilayer Structure

The polymer electroluminescence (EL) device with PBD as carriers confinement layer yields bright blue emission having intensity of 300cd/m², in same case the device without PBD layer have luminance only 44 cd/m². The effect of PBD layer on EL characteristic was studied. The results show that only in EL devices with PBD thick-ness over 30nm, the holes are completely confined in emitting layer. The luminance over 2000cd/m² can be obtained by inserting an electron injecting layer between the negative electrode and PED to increase the electron injection.