A review on fabrication processes for electrochromic devices

Electrochromism is a phenomenon involving change of colors under an externally applied voltages Because its importance is rising today, various fabrication processes have been used to manufacture electrochromic devices (ECDs). In this review, solution-, vapor-, and solid particle-based processes are introduced and compared in terms of process parameters. The seven representative fabrication processes discussed in this paper are electrodeposition, sol-gel, spray pyrolysis, chemical vapor deposition (CVD), thermal evaporation deposition, sputtering, and nanoparticle deposition systems (NPDS). Temperature and vacuum conditions for each process are compared. Electrodeposition and sol-gel processes can be performed under atmospheric pressure. Most sputtering and NPDS processes are conducted at room temperature. Although many fabrication processes are reviewed here, commercialization, environmental issues, cost, improvement of performance, and enhancement of product size will be studied for future ECDs.