National Renewable Energy Laboratory, Golden, CO 80401, USA.
Nanotechnology. 2012 Jun 29;23(25):255601. doi: 10.1088/0957-4484/23/25/255601. Epub 2012 May 31.
A low-temperature ozone exposure technique was employed for the post-treatment of WO(x) nanorod thin films fabricated from hot-wire chemical vapor deposition (HWCVD) and ultrasonic spray deposition (USD) techniques. The resulting films were characterized with x-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, UV-vis-NIR spectroscopy and x-ray photoelectron spectroscopy (XPS). The stoichiometry and surface crystallinity of the WO(x) thin films were subsequently modulated upon ozone exposure and thermal annealing without particle growth. The electrochromic performance was studied in a LiClO(4)-propylene carbonate electrolyte, and the results suggest that the low-temperature ozone exposure technique is superior to the traditional high-temperature thermal annealing (employed to more fully oxidize the WO(x)). The optical modulation at 670 nm was improved from 35% for the as-deposited film to 57% for the film after ozone exposure at 150 °C. The coloration efficiency was improved and the switching speed to the darkened state was significantly accelerated from 18.0 s for the as-deposited film to 11.8 s for the film after the ozone exposure. The process opens an avenue for low-temperature and cost-effective manufacturing of electrochromic films, especially on flexible polymer substrates.
采用低温臭氧处理技术对热丝化学气相沉积（HWCVD）和超声喷雾沉积（USD）技术制备的 WO(x)纳米棒薄膜进行后处理。用 X 射线衍射（XRD）、透射电子显微镜（TEM）、拉曼光谱、紫外可见近红外光谱和 X 射线光电子能谱（XPS）对所得薄膜进行了表征。随后，在不引起颗粒生长的情况下，通过臭氧暴露和热退火来调节 WO(x)薄膜的化学计量比和表面结晶度。在 LiClO(4)-碳酸丙烯酯电解质中研究了电致变色性能，结果表明，低温臭氧处理技术优于传统的高温热退火（用于更完全地氧化 WO(x)）。在 670nm 处的光学调制从沉积后薄膜的 35%提高到 150°C 臭氧暴露后的薄膜的 57%。着色效率提高，从沉积后薄膜的 18.0s 到臭氧暴露后的薄膜的 11.8s，对深色状态的开关速度显著加快。该工艺为电致变色薄膜的低温和低成本制造开辟了道路，特别是在柔性聚合物衬底上。
