Reactive ion etching of sol–gel-processed SnO2 transparent conducting oxide as a new material for organic light emitting diodes

This paper reports on the potentialities of sol–gel-deposited Sb-doped SnO2 (TO) as a new transparent conducting oxide (TCO) for anode in organic light emitting diodes (OLED). Multilayered films with transparency over 85% and resistivity lower than 5×10−3 Ω cm were obtained. The films are nano-crystallized and the surface roughness does not exceed 20 Å. TO films are very stable and cannot be chemically etched. Anode patterning by reactive ion etching in a methane–hydrogen plasma is described. Typical etching around 250 Å/min were obtained. TO/PEDOT/PVK/Al hole only diodes were realized to assess the TO material as hole injection electrode. Devices with threshold voltages of 6 V were obtained. A comparison with indium tin oxide deposited by low temperature cathodic sputtering is given.