中频磁控溅射制备氧化钨薄膜及电致变色性能研究

Study on Electrochromic Properties of Tungsten Oxide Films Deposited by Medium Frequency Magnetron Sputtering

采用中频磁控溅射方法,在氧化铟(ITO)玻璃上采用氧化钨(WO_(3))陶瓷靶沉积薄膜,研究溅射气压对WO_(3)薄膜结构与光学性能的影响规律,并对其电致变色行为进行了探讨。采用X射线衍射(XRD)和扫描电子显微镜(SEM)分析了WO_(3)薄膜的成分结构和表面形貌,紫外可见分光光度计和电化学工作站对薄膜的光调制性能、电致变色伏安特性、以及循环寿命性能进行了研究,并利用X射线光电子能谱(XPS)对WO_(3)薄膜在着色、褪色状态下进行了化学成分及氧化状态分析。结果表明:随着溅射气压的增大,WO_(3)薄膜的形貌结构变得疏松、粗糙,更有利于Li+的注入与脱出,响应速度变快、调制幅度增大、电致变色性能优异,但循环寿命性能有所降低。当溅射气压为4Pa时WO_(3)薄膜的电致变色综合性能最好,在550nm处的调制幅度可达81.0%,着色、褪色响应时间分别为7.8s、5.85s,且在1500次循环后,仍保持较高的电致变色性能。

The tungsten oxide(WO_(3))films on transparent conductive indium oxide glass were prepared by mid-frequency magnetron sputtering technique.The effect of sputtering pressure on the microstructure and optical properties of WO_(3) thin films was studied.The composition and surface morphology of WO_(3) films were analyzed by X-ray diffraction analysis and scanning electron microscopy.The electrochromic voltammetry,light modulation and cycle life of the WO_(3) films were studied by electrochemical workstation and UV-Vis spectrophotometer.The chemical composition and oxidation state of WO_(3) film in the state of coloring and bleaching were analyzed by X-ray photoelectron spectroscopy.The results show that the WO_(3) films are all amorphous.With the increase of sputtering pressure,the morphology of WO_(3) films structure becomes loose and rough,which is in favor of the intercalation/de-intercalation of Li+.The films deliver the fast response speed,wide amplitude modulation and excellent electrochromic performance,however,the poor cycling stability.When the sputtering pressure is 4 Pa,the best electrochromic properties with the modulation amplitude of 81.0%at 550 nm and coloring/bleaching response time of 7.8 s/5.85 s were obtained,which were well maintained after 1500 cycles.