Tungsten oxide(WO3) films with uniform surface morphology are fabricated using a spin-coating method for applications of electrochromic(EC) devices. To improve the EC performances of the WO3 films, we control the heating rate of the annealing process to 10, 5, and 1 oC/min. Compared to the other samples, the WO3 films fabricated at a heating rate of 5 oC/min shows superior EC performances for transmittance modulation(49.5 %), response speeds(8.3 s in a colored state and 11.2 s in a bleached state), and coloration efficiency(37.3 cm2/C). This performance improvement is mainly related to formation of a uniform surface morphology with increased particle size without any cracks by an optimized annealing heating rate, which improves the electrical conductivity and electrochemical activity of the WO3 films. Thus, the WO3 films with a uniform surface morphology prepared by the optimized annealing heating rate can be used as a potential candidate for performance improvement of the EC devices.

Abstract
 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)
• 구본율(서울과학기술대학교 의공학-바이오소재 융합 협동과정 신소재공학프로그램) | Bon-Ryul Koo (Program of Materials Science & Engineering, Convergence Institute of Biomedical Engineering and Biomaterials, Seoul National University of Science and Technology)
• 안효진(서울과학기술대학교 신소재공학과, 서울과학기술대학교 의공학-바이오소재 융합 협동과정 신소재공학프로그램) | Hyo-Jin Ahn (Department of Materials Science and Engineering, Seoul National University of Science and Technology, Program of Materials Science & Engineering, Convergence Institute of Biomedical Engineering and Biomaterials, Seoul National University of Science and Technology) Corresponding author