Evaluation of V2O5 Film-Based Electrochromic Device with Dry-Deposited Ion Storage Layer

Abstract

Vanadium pentoxide (V2O5) film was used to fabricate an electrochromic device counterbalanced with a dry-deposited ion storage layer (ISL). For the ISL, a mixture of antimony-doped tin oxide (ATO) and Prussian blue (PB) powders (PB-ATO; 1:4 vol%) was dry deposited to form PB-ATO ISL as the counter electrode of the device, thereby improving electrochromic device characteristics. Dry deposition provided a film with a rough surface, which resulted in improved electrochromic properties because of the large surface area of the ISL, which provided more paths for electron movement. The ISL was deposited using a dry deposition system (i.e., the nanoparticle deposition system [NPDS]) to maximize the surface area of the film. The polyol method was used to fabricate V2O5 film with high crystallinity for better electrochromic properties. The fabricated V2O5-based electrochromic device (ECD) was evaluated by electrochemical analysis. Compared with the ECD without PB-ATO ISL, the difference in reflectance exceeded 50% for the ECD with PB-ATO ISL. Moreover, the ECD without ISL had a diffusion coefficient of 1.88 x 10(-10) S-2/s, while the ECD with PB-ATO ISL had an order of magnitude higher diffusion coefficient of 2.47 x 10(-9) cm(2)/s. Therefore, the performance of the ECD was improved using dry-deposited ISL composed of PB-ATO. The coloration of the device was dramatically improved using PB-ATO ISL, compared with the device with ATO alone or without any ISL.