Application of an evaporable fluoro-molecule as an anode buffer layer in organic electroluminescent devices

We have synthesized a small molecule fluoro-material, N,N,N′,N′-tetra(4-methylphenyl)-2,2′,3,3′,5,5′,6,6′-octafluoro-biphenyl-4,4′-diamine (POFDA), as an anode buffer layer for organic light-emitting devices (OLEDs). This fluoro-material shows obvious hydrophobicity, which stabilizes the indium-tin oxide (ITO) surface from moisture and air contaminants. In addition, insertion of an ultrathin POFDA layer at the ITO/organic interface significantly reduces operating voltage, and increase efficiency, and operational stability. Ultraviolet photoelectron spectroscopic analysis suggested that the performance improvement is related to the reduction in hole-injection barrier at the anode contact.