Driving voltage reduction through non-radiative charge recombination interfaces in organic light-emitting diode

We report a new way for the driving voltage reduction through non-radiative charge recombination interfaces in organic light-emitting devices (OLEDs). Non-radiative charge recombination interfaces made between a hole transporting layer and a deep lowest unoccupied molecular orbital (LUMO) electron transporting layer results in significant increase of hole current conduction, which finally could give us voltage reduction in OLEDs. Such voltage reduction is attributed to strong columbic interaction at charge recombination interfaces. Voltage reduction from 5.2 to 4.3 V at 1000 cd/m2 in fluorescent blue devices is demonstrated with this our concept. Our suggested structure of non-radiative charge recombination interfaces can be very useful for many practical organic semiconductor device applications.