Anode/organic interface modification by plasma polymerized fluorocarbon films

The effects of plasma polymerized fluorocarbon films (CF_x) on device performance in organic light-emitting diodes (OLED) were analyzed. OLEDs with a 0.3-nm thick CF_x film on an untreated indium tin oxide (ITO) anode showed identical current density-voltage characteristics and improved operational stability. By the formation of an artificial dipolar layer resulting from rich, negatively charged fluorine, the enhancement of hole injection was attributed to the manipulation of the energy level offset at the anode/organic interface. It was found that the dipolar interface was fairly stable when being exposed to air.