Fabrication of IZO transparent conducting thin films by the use of magnetron sputtering equipped with ion-beam system

Indium zinc oxide (IZO) thin films have been prepared on glass, polycarbonate (PC), and polyethylene terephthalate (PET) substrates by using a radio-frequency (RF) magnetron sputtering system equipped with an ion gun, and a simple OLED device was made by using IZO film. The influence of the RF power, the Ar gas volume, and the substrate temperature during the deposition process on the roughness and the electrical and optical properties of the films have been investigated. In addition, End-Hall ion-beam treatment of the substrates is applied before the sputtering deposition process. The sheet resistance of the IZO films is 25 Omega/square for the glass, 21 Omega/square for the PC, and 20 Omega/square for the PET substrate with a thickness of 150 nm, and the lowest root-mean-square (rms) roughness of these IZO films were measured to be 0.58, 0.35, and 0.32 nm for glass, PC, and PET substrate, respectively. The decrease in the sheet resistance of the IZO films becomes evident after the ion-beam treatment and makes the surface of the thin film more hydrophilic. Relative to non-treated IZO film, the ion-beam-treated IZO anode in the OLED device seems to inject holes into the emitting layer to enhance the current density.