A Study Of Preparation And Characterization Of Cu_xZn_yS Ternary Sulfide Flexible Transparent Conductive Thin Film

As common sulfide materials,Zn S has favorable light transmittance but slightly poor conductivity.On the contrary,although Cu S has poor light transmittance,its high electrical conductivity is comparable to that of metal materials.If the characteristics of the two materials are well combined,it is expected to develop a film with both good light transmittance and conductivity,which lays a foundation for the wide application of transparent electronic devices.Therefore,the research and development of Cu_xZn_yS ternary sulfide film materials is of great significance in the research field of transparent conductive films.In this study,Cu_xZn_yS ternary sulfide transparent conductive films with excellent performance were prepared by chemical bath deposition method in two different precursor solution systems,acidic and alkaline,respectively.The light transmittance and conductivity of samples were tested by UV-visible spectrophotometer and four-probe resistance tester.The elemental composition,morphology and structural characteristics of samples were characterized by scanning electron microscope with EDS spectrometer and X-ray diffractometer.Finally,the optimized experimental parameters were scaled up to obtain a large-size transparent conductive film.The uniformity of the film was investigated by testing the light transmittance and the sheet resistance value of different regions.The adhesion of film with flexible PET substrate was determined using the 3M tape test method.The flexural resistance of film was tested by a self-made film conductive bending test device,and the change of resistance after different bending degrees and bending times was analyzed.The test results show that under acidic conditions,a p-type transparent conductive film with composition of Cu_0.28Zn_0.60S was obtained by adjusting and optimizing the experimental conditions such as the type and concentration of each reactant,p H value of precursor solution,reaction temperature,reaction time and post-treatment temperature.The obtained film has a sheet resistance of 82.3?/?and a light transmittance of 73.8%.The adhesion level between the film layer and PET substrate is 5B grade,indicating its good binding fastness.Under alkaline conditions,a p-type transparent conductive film with composition of Cu_0.29Zn_0.62S was obtained by optimizing the experimental conditions above all.It has best comprehensive performance with sheet resistance of 129.3?/?and light transmittance of 72.5%.Then,the process parameters are scaled up,and the large-size film obtained still maintains good electrical conductivity and light transmission performance.The measured performance data of each area of the film has little fluctuation,indicating its good uniformity.In addition,the films have excellent flexural resistance in both acidic and alkaline systems,as their conductivities are substantially stable after thousands of large-scale bending operations.