Preparation And Properties Of Electrochromic Devices Based On Ion Implantation And Reversible Metal Electrodeposition

Electrochromic devices are mainly divided into ion implantation devices and reversible metal electrodeposition devices in terms of working mechanism.At present,the amount of optical modulation of injection-type devices is small,which can not achieve complete shading,and the response speed is slow.Reversible metal electrodeposition devices have a large amount of optical modulation,and can achieve a transmissivity of less than 5%in the colored state.However,the device requires that the fading voltage be less than the deposition voltage of metal ions,otherwise reverse coloring will occur,limiting the application range of the device.In this study,a device with an intermediate electrode structure is proposed.By applying voltage between the intermediate electrode and the colored electrode,the device fades,thus breaking the limit of the range of the fading voltage and improving the fading response speed.At the same time,the injection device can be combined with the working mechanism of reversible metal electrodeposition device to produce a device that can switch freely between the transparent state,mirror state,black state and blue state.The specific research contents are as follows:（1）Nano-structured WO₃electrochromic films were prepared by metal doping induced growth technology.The first step is to use the magnetron sputtering method to induce the growth of WO₃ nanoparticle seed layer film through Ag doping.The average radius of WO₃ nanoparticle obtained under the optimal process conditions is 136 nm,and the density is about 1.24/μm²。The second step is to use the magnetron sputtering method to induce the growth of WO₃ nanopillar like thin films on the seed layer of WO₃nanoparticles through Gd doping.The average height of WO₃ nano-columns prepared under the optimal process conditions is 850 nm,the bottom diameter is 240 nm the aspect ratio is 3.54,and the density is about 0.31/μm²。（2）On the basis of the prepared WO₃ nano-column structure film,a combined polychromatic electrochromic device was assembled and optimized:the response time of the device was accelerated by adding copper chloride（CuCl₂）and tetrabutylammonium bromide（TBABr）into the solution;By introducing the intermediate electrode structure,the range limit of the fading voltage of the device is broken;The contact area between the intermediate electrode and the electrolyte solution is increased by using a stepped gasket.（3）The electrochromic and electrochemical properties of the prepared electrochromic devices were tested by the performance characterization and cause analysis.Optical modulation between mirror and transparent statesΔT is 67.7%（at the wavelength of 600 nm,the transparent transmittance of the device is 71.7%,and the colored transmittance is 4%）,the coloring time T_c is 7.1 s,and the fading time T_b is 4.6 s;The optical modulation between the black and transparent states of the deviceΔT is 60.8%（at the wavelength of 600 nm,the transparent transmittance of the device is 71.7%,and the colored transmittance is 10.9%）,the coloring time T_cis 9.9 s,and the fading time T_bis 7.8 s;Optical modulation between blue and transparent states of the deviceΔT is 66.4%（at the wavelength of 600 nm,the transparent transmittance of the device is 71.7%,and the colored transmittance is 5.3%）,the coloring time T_c is 9.5 s,and the fading time T_b is14.1 s.The device still has good performance stability after 500 cycles of testing.