Zao/cu/zao Transparent Conductive Film Preparation And Characteristics Of The Study

The requirements to transparent conductive film (TCO) are ever-increasing, with the rapid development of the flat panel display technology and optoelectronic devices. Currently In2O3:Sn(ITO) film was the most widely used transparent conductive film, ZnO3Al(ZAO) films as a representative of the new generation of transparent conductive films have the trend of replacing the ITO film. Nevertheless, semiconductor transparent conductive film is limited by the semiconductor conductive mechanism can no longer meet the increasing requirements of people. Thereupon, metal sandwich transparent conductive composite film arises. It has important value to deeply investigate the preparation principles and process technology of ZAO/Cu/ZAO multilayer films.In this work, the ZAO/Cu/ZAO multilayer films was fabricated by direct current (DC) magnetron sputtering method on glass substrate. The modern analytical techniques such as X-ray diffraction, atomic force microscopy, ultraviolet and visible spectrophotometer, four point probe were used to characterize crystalline structures, surface morphology and photoelectric properties of the samples. The effect of parameters of the film thickness, the temperatures of sputtering and thermal annealing on the structure, optical properties of ZAO/Cu/ZAO multilayer films were investigated and analyzed.The experimental results show that the Cu layer thickness has a decisive influence on the photoelectric properties of ZAO/Cu/ZAO multilayer films, the best thickness of Cu layer is8nm. The effect of the top ZAO layer on the surface roughness and transmittance of samples is more obvious than that of the bottom ZAO layer. When the thickness matches the best structure50nm/8nm/50nm, the multilayer films has a low sheet resistivity of10.10Ω/(?) and a high visible light transmittance of85.78%, and the merit figure (FTC) is2.14×10-2Ω-1.An improved figure of merit of2.65×10-2Ω-1is obtained for the multilayer deposited at100℃with an average transmittance of86.64%and a resistivity of9.8×10-5Ω cm. The photoelectric properties of the multilayer films get worse when the sputtering temperature reaches to150℃. The rapid annealing treatment can improve Cu crystallinity as well as the photoelectric properties of multilayer films. The highest figure of merit of3.54×10-2Ω-1is obtained for the multilayer annealed at100℃with a resistivity of8.81×10-5Ω. cm and an average transmittance of88.33%.