Study Of Oxide/Metal/Oxide Stacked Transparent Conductive Thin Films

Transparent Conductive Oxide Thin Films(TCOs)are widely used in flat panel displays,solar cells,and other fields due to their metal-like conductivity and glass-like high light transmittance.According to the development of transparent conductive oxide films,ITO is the most widely used and has the best comprehensive properties.However,metallic indium is a scarce resource,so it will lead to high ITO costs.Therefore,this paper focuses on the Nb2O5-based multilayer transparent conductive film to replace ITO.This article mainly uses the method of magnetron sputtering to prepare three kinds of multilayer oxide films of Nb2O5/Ag/Nb2O5,Nb2O5/Ag/ZnO and Nb2O5-ZnO/Ag/Nb2O5-ZnO at room temperature.Mainly from the following aspects of research:(1)The upper and lower metal oxide films were prepared by RF magnetron sputtering,and the effect of the thickness on the performance of the multilayer electrode was analyzed.(2)The intermediate metal layer Ag was prepared by direct current(DC)magnetron sputtering.The influence of Ag film thickness and grain size of Ag film on the whole multilayer electrode was analyzed.(3)Nb2O5 and ZnO mixed films were prepared by radio frequency(RF)magnetron sputtering.We prepare multilayer electrodes,analyzing their properties and discussing their photoelectric properties.In Chapter 3,Nb2O5 layers were prepared by RF magnetron sputtering.The Ag layer was prepared by DC magnetron sputtering.The transparent conductive films with Nb2O5/Ag/Nb2O5 sandwich structure were prepared on glass substrates.The structure and morphology of the films were characterized by scanning electron microscopy(SEM)and X-ray diffraction(XRD).The optical and electrical properties of the films were measured by UV-visible spectrophotometer and four probes.The specific results are as follows:(1)By controlling the sputtering time of Nb2O5,the film thicknesses are 10 nm,20 nm,30 nm,and 40 nm,respectively.By comparing the transmission spectrum,it can be concluded that when the Nb2O5 film thickness is 30 nm,the whole multilayer electrode has the best transmittance.We change the sputtering power of Nb2O5 to 50 W,100 W,and 150 W separately.We can find the best optimum sputtering power was 100 W.(2)The thickness of the Ag film has a great influence on the light transmittance and the conductivity of the film.We keep the thickness of the Nb2O5 film unchanged,and change the thickness of the Ag to 5 nm,10 nm,and 15 nm,respectively.When the thickness of the Ag film was increased from 5 nm to 10 nm,the electrical conductivity of the film dropped from several tens ofEuros to several Euros,and the light transmittance was also improved.When the thickness of Ag film continues to increase to 15 nm,the resistance becomes smaller,but the transmittance decreased.Therefore,when the thickness of the Ag film is 10 nm,the film has the best photoelectric characteristics,the film surface resistance is 7.8 ?/sq,and the light transmittance reaches 90%.In Chapter 4,we chose to use ZnO instead of a layer of Nb2O5 to improve the performance of the entire electrode.The Nb2O5 layer and the ZnO layer were sputtered by radio frequency,and the Ag layer was DC-sputtered.Scanning electron microscopy(SEM)and X-ray diffraction(XRD)were used to characterize the structure and morphology of the films.The optical and electrical properties of the films were measured with a UV-visible spectrophotometer and four probes.The specific findings are as follows:(1)First,compare the advantages and disadvantages of Nb2O5/Ag/ZnO and ZnO/Ag/Nb2O5 multilayer films.It can be seen from the light transmission and conductivity analysis that the performance of Nb2O5/Ag/ZnO films is better than that of ZnO/Ag/Nb2O5 films.(2)The influence of the thickness of ZnO film on the optoelectronic properties of the electrode was investigated.The thickness of fixed Nb2O5 was invariable,and the thickness of ZnO was changed to 24 nm 30 nm 36 nm and 42 nm respectively.When the thickness of ZnO was increased to 36 nm,the transmittance of the whole film was over 90%.And the surface resistance of the film is only 5.6 ?/ sq.(3)The flexibility and stability of the electrode are tested.The results show that the flexibility of the electrode is good and the performance of the electrode is still stable after six months of placement.In chapter 5,Nb2O5 and ZnO mixed films were prepared by RF magnetron sputtering,and Ag films were prepared by DC magnetron sputtering.The structure and morphology of the films were characterized by scanning electron microscopy(SEM)and X-ray diffraction(XRD);the optical and electrical properties of the films were measured with a UV-visible spectrophotometer and four probes..The experimental results show that Nb2O5 and ZnO hybrid films are high quality optical films.The transmittance of Nb2O5-ZnO/Ag/Nb2O5-ZnO multilayer films in the visible light range reached 94.3%,and the film surface resistance was 3.4 ?/sq.