Improved Performance of Organic Light Emitting Devices Using Triazole/ Cs_2CO_3/Al Cathode

摘要

In this study, a new cathode system of triazole (TAZ)/Cs_2CO_3/Al has been proposed. Obvious efficiency improvement and sharp enhanced electron injection were maintained in the devices with this new cathode. TAZ owns deep the highest occupied molecular orbital (HOMO) and wide band gap, so as to block the hole leakage effectively and confine the exciton in Alq_3 emissive layer. An abrupt lowering of the vacuum level was found in the mixture of TAZ and Cs_2CO_3, which indicated that the electron injection barrier from metal cathode into Alq_3 was greatly reduced. Our experimental proved that this new cathode may have a wide application in OLEDs emitting light with short wavelength.