In the present study, vanadium oxide(V2O5) films for electrochromic(EC) application are fabricated using sol-gel spin coating method. In order to optimize the EC performance of the V2O5 films, we adjust the amounts of polyvinylpyrrolidone(PVP) added to the solution at 0, 5, 10, and 15 wt%. Due to the effect of added PVP on the V2O5 films, the obtained films show increases of film thickness and crystallinity. Compared to other samples, optimum weight percent(10 wt%) of PVP led to superior EC performance with transmittance modulation(45.43 %), responding speeds(6.0 s at colored state and 6.2 s at bleached state), and coloration efficiency(29.8 cm2/C). This performance improvement can be mainly attributed to the enhanced electrical conductivity and electrochemical activity due to the increased crystallinity and thickness of the V2O5 films. Therefore, V2O5 films fabricated with optimized amount of PVP can be a promising EC material for high-performance EC devices.

Abstracts
 1. 서 론
 2. 실험 방법
 3. 결과 및 고찰
 4. 결 론
 References

• 김규호(서울과학기술대학교 신소재공학과) | Kue-Ho Kim (Department of Materials Science and Engineering, Seoul National University of Science and Technology)
• 배주원(서울과학기술대학교 신소재공학과) | Ju-Won Bae (Department of Materials Science and Engineering, Seoul National University of Science and Technology)
• 이태근(서울과학기술대학교 신소재공학과) | Tae-Kuen Lee (Department of Materials Science and Engineering, Seoul National University of Science and Technology) Corresponding author
• 안효진(서울과학기술대학교 신소재공학과) | Hyo-Jin Ahn (Department of Materials Science and Engineering, Seoul National University of Science and Technology) Corresponding author