Transparent conductive film having sandwich structure of gallium-indium-oxide/silver/gallium-indium-oxide

New transparent conductive films having the sandwich structure of gallium-indium-oxide/silver/gallium-indium-oxide (GIO/Ag/GIO) were prepared by conventional magnetron sputtering method at ambient substrate temperature. The electrical and optical properties of the films were compared with those of conventional indium-tin-oxide (ITO) films and ITO/Ag/ITO sandwich films. The GIO/Ag/GIO (40 nm/8 nm/40 nm) sandwich films, in which the GIO film was deposited using a GIO ceramic target with In content [In/(Ga+In)] of 10 at.%, exhibited a low sheet resistance of 11.3 Omega/sq and a large average transmittance of over 92.9% in the visible region (400-800 nm). This GIO/Ag/GIO films also exhibited a novel characteristic of transparency in the ultraviolet region; they showed high transmittance of 82.2% at the wavelength of 330 run and 40.8% at the wavelength of 280 nm, which was not shown in the ITO films and the ITO/Ag/ITO sandwich films. The GIO/Ag/GIO sandwich films are useful as transparent electrode for emitting devices of ultraviolet radiation because of both their high conductivity and high transparency in the ultraviolet region. (c) 2007 Elsevier B.V. All rights reserved.