Preparation And Characterization Of TiO₂ And ZnO Multilayer Transparent Electrodes Sandwiched Ag Film

Here, we parepared TiO₂/Ag/TiO₂, TiO₂/Ag/ZnO and ZnO/Ag/ZnO multilayers by room-temperature magnetron sputtering. The sputtering power, thickness of films and the concentration of O₂ introduced into the Ag deposition are analyzed to optimize the performance of multilayer. The scanning electron microscopy, X-ray diffraction, UV/visible spectrometer,four-point probe system and electronic tensile testing machine were used to characterized morphology, structure, transmittance, conductivity and ductility of multilayers.First, the conductivity of TiO₂/Ag/TiO₂ with optimal sputtering parameters for optimal thickness of TiO₂ and Ag layers is poor due to amorphous TiO₂ at the room temperature.The conductivity can be greatly improved by annealing but the experimental process become very complex, leading to the TiO₂/Ag/TiO₂ is not suitable for transparent electrode.The ZnO with high carrier concentration and mobility can make up the defect of poor conductivity of TiO₂. Because the morphology of Ag grown on TiO₂ was better than that of ZnO, we prepared TiO₂/Ag/ZnO multilayer films. Then the TiO₂/Ag/ZnO achieved the best performance with transmittance of 94.3% and sheet resistance of 5.2 Ω/sq by optimize the preparation parameters, such as film thickness and sputtering power.High transparent, conductive, and stable ZnO/Ag/ZnO flexible electrodes were achieved by a percentage of O₂ in Ar atmosphere was introduced when sputtering Ag film. The oxidization- induced effect under the Ar atmosphere with tiny O₂ guides the Ag to form continuous film and evenly deposit on ZnO film. When the concentration of O₂ in Ar atmosphere was 2.0%³.0%, ZnO/Ag/ZnO films showed visible-range transmittance of 95.9% and sheet resistance of 7.11 Ω/sq. In addition, proper oxygen concentration also helps to improve performance of TiO₂/Ag/ZnO flexible electrode and the TiO₂/Ag/ZnO electrodes achieve 94.8% visible transmittance, 3.5 Ω/sq sheet resistance.