The Preparation And Performance Of Electrochromic Poly(3,4-Ethylenedioxythiophene) Film

Poly(3,4-ethylenedioxythiophene), which is usually abbreviated to PEDOT, is a widely used conductive polymer. It has been extensively studied because of their wide applications in the filed of electrochromic, electroluminescent, dye sensitized solar cell, photoelectric devices and other electric energy storage devices as the function layer, conductive layer and hole transport layer. Compared with other electrochromic materials, PEDOT is restricted by its low color contrast and short cycle life in the pratical application. In order to improve the electrochromic performance of PEDOT film, this paper demonstrates the effects of deposition factors in electrodeposition process on electrochromic performance. The influence of three dimensional order macroporous structure on electrochromic performance also were studied. Finally, a new electrochromic device, which just employ same polarity coloring material, was designed and assembled. At the same time, a series of algorithm which can use in Smart Windows was compiled. The algorithm aimed at switching the color of the device according as outside temperature.The PEDOT electrochromic film was polymerized under condition of constant potential in the ionic liquid, then the impact of film properties was discussed the deposition voltage, monomer concentration and deposition time. The research results show the best performance film can be obtained in a deposition solution consisting of 0.1 M EDOT monomer and 1 M [Bmim]PF6 under the condition of 1.20 V for 40 s.The best film exhibited an ideally contrast ratio of 61.8%, a noticeable coloration efficiency of 238.7 cm 2 C-1, and a shortened coloration time of 0.74 s.The 3DOM PEDOT Film was electropolymized in ITO glass coated with PS template of different diameter of 428 nm, 552 nm, 702 nm under the condition of 1*10-4 mA/cm2 constant current, then the film was steeped into the tetrahydrofuran for 10 h-12 h. The diffusion rate of 3 kinds of 3DOM PEDOT film and the unstructured one was tested and calculated, the research showed that the 3DOM structured film diffusion rate is greater than the unstructured film a number level. These macrostructures can effectively reduce the coloration potential of the film, and the 3DOM can significantly improve the electrochromic cycle performance, the unstructured film revealed the contrast attenuation of 89% after 900 cycles, while the contrast of 428 nm diameter three-dimensional ordered macroporous film attenuated by 55% after 3000 cycles. The transmittance wave trough of 3DOM structure films were redshift, which 703 nm diameter 3DOM PEDOT film wave trough of the redshift 58 nm. Bragg reflection ordered structure gives the film new reflective color.Compared with single electrochromic device, the contrast of new devices increase from 40 % to 55 %, then attenuated to 47 % after 300 cycles, the coloring time reduced from 362 ms to 203 ms, the coloration efficiency increase from 91.18 cm2·C–1 to 181.55 cm2·C–1. A temperature control algorithm had be designed, and it had be compiled as part of the algorithm C language then uploaded to the microcontroller RAM. The electrochromic device can be colored or faded according to the outside temperature.