C60:LiF nanocomposite for high power efficiency fluorescent organic light-emitting diodes

To reduce the driving voltage, and hence enhance the power efficiency of OLEDs, the mobility of the various carrier transport layers needs to be increased. Buckminsterfullerene (C(60)) has been proposed to be one possible alternative conductive electron transport layer (ETL) to enhance the power efficiency in OLEDs, due to its high conductivity and the formation of an ohmic contact with the LiF/Al cathode. The optical properties of a nanocomposite of C(60) with LiF (C(60):LiF) and its potential as an efficient ETL in OLEDs was studied. With proper optimization of the device structure, a more than 50% improvement in the power efficiency, without sacrificing the high EQE, in optimized fluorescent OLEDs with the use of C(60):LiF nanocomposite ETL was achieved.