Template Preparation Of Flexible Transparent Conductive Film Based On Particle-Free Silver Ink

Transparent conductive film is a type of optoelectronic core material that combines light transmittance and conductivity.It is widely used in the electronic information industry,biomedical field,and automotive industry.The rapid development of current social science and technology and the rapid growth of the transparent conductive film market have made electronic devices in the future more intelligent,wearable and flexible.Indium tin oxide(ITO),a traditional material for preparing transparent conductive films,has excellent electrical and optical properties,but the scarcity,toxicity,and brittleness of metal indium have led to an increase in the production cost of ITO coated substrates.It also limits the applicability of ITO to temperature-sensitive flexible substrates.This dissertation proposes to use particle-free silver ink as the silver source,and independently develop the template method and spin coating process to prepare a flexible silver grid transparent conductive film,which can control the morphology of the silver grid and independently adjust the transmittance and conductivity of the film.Its properties have been studied,making it a substitute for flexible electrode materials.The main findings include:1.Based on low-cost template method and spin coating process,templates with different crack morphology were prepared.The coating speed,the coating time,the spin coating speed and the spin coating time in the spin coating process were investigated.The effects of different heating rate and holding temperature on the crack line width after cracking of acrylic emulsion film and the size of mesh formed by intertwining different cracks were investigated.The study found that the optimum process of the template method is the spin coating condition of uniform coating speed of 500 r/min,uniform coating time of 15 s,spin coating speed of 5000 r/min,and spin coating time of 20 s.Moreover,the temperature is raised to 200? at a heating rate of 200?/h to keep dry,and a uniform template with a fine line width and a dense mesh can be obtained.Finally,a silver grid transparent conductive film with a transmittance of 83%and a sheet resistance of 42 ?/sq can be obtained.The silver grid can be completely embedded in the crack template groove,and the finest silver grid line width reaches 1 ?m.It achieves independently adjustable performance of transmittance and conductivity,and better meets the different applications of actual devices.2.A flexible transparent conductive film was prepared by gradually moving from the hard glass substrate to the flexible substrate.Combined with the spin coating process and ultrasonic stripping technology,the coating and removal of the acrylic emulsion crack template was completed.Combined with the coating of the non-particle silver ink,the preparation of the flexible transparent silver mesh film was realized,and the mechanism of silver ink immersion crack was explored.From the experimental aspects,the effects of ultrasonic cleaning agent ratio and ultrasonic time on the removal of crack templates were studied in detail.And the effect of the flexible PET substrate on the flexibility of the film,and roughly explored the change in resistance of the film during the bending process.The results show that in the ultrasonic cleaning agent,when the absolute ethanol:deionized water=2:1,and the ultrasonic time is 5 min,the crack template on the substrate can be removed intact.Finally,a flexible silver mesh transparent conductive film with a transmittance of 82%and a square resistance of 28 ?/sq was obtained,and the film resistance did not change significantly after 100 bendings,effectively overcoming the poor flexibility of ITO films.3.This dissertation compares the fluidity of particle-free silver ink on different substrates.The effects of different solvent amount and heat treatment temperature on the microstructure and sheet resistance of the silver film were studied,which ensured that the surface of the silver grid transparent conductive film was flat and the particle growth inside each wire in the silver grid was uniform and the roughness was small.Studies have shown that the amount of solvent in the non-particle silver ink is 1 mL,and heat treatment drying at 200? at a heating rate of 200?/h can ensure uniform growth of the grain in the microstructure of the silver film on the substrate,the sheet resistance of the film is 0.55 Q/sq.Too high or too low a drying temperature is not conducive to improving the electrical conductivity of the silver film.The resulting flexible random silver mesh film has a roughness of 3 nm.The problems of uneven growth,high roughness and high heat treatment temperature of the silver film particles grown on the substrate are improved.