Carrier injection in organic electronics: Injection hotspot effect beyond barrier reduction effect

An alternative strategy, making a number of injection hotspots at the nanoscale on the electrode surface to reinforce the local electric field, is proposed for achieving efficient carrier injection in organic electronic/optoelectronic devices. The injection hotspot effect can be dominant at the metal/organic contacts with a high carrier injection barrier, when the barrier reduction effect is not applicable. In the present case, a tiny amount of fullerene and its derivative on ITO do not significantly change the injection barrier but form the injection hotspots which enhance the electron injection and greatly reduce the operation voltage in the inverted organic light-emitting diodes.