Optical and electrical effects of nickel oxide interlayer for anode-recessed organic light-emitting diodes

Forming a nickel oxide (NiOx) layer on recessed indium tin oxide (ITO) anodes has successfully enhanced the current efficiency of an organic light emitting diode (OLED) by up to 46%. The recesses largely increased the haze of ITO film and led to a 32.8% current efficiency enhancement of a planar OLED. The introduced NiOx interlayer allowed another 12.9% efficiency enhancement mainly due to lowered potential barrier at the ITO/organic interface and further elevated haze that led to a more efficient light extraction.