三氧化鎢/氧化矽複合薄膜之製備與其電化學與電致色變性質之研究

本研究以金屬鎢粉和雙氧水為起始物，添加四乙氧基矽烷(Tetraethyl orthosilicate, TEOS, Mw=208.33g/mol)並以無水乙醇為溶劑製備前驅物，利用溶膠/凝膠法搭配旋轉塗佈法，於FTO導電基材上製備三氧化鎢(WO3)薄膜。藉由改變鎢與矽之莫耳比，修飾所得三氧化鎢薄膜之微結構。利用掃描式電子顯微鏡對薄膜進行表面成分，利用FTIR進行化學鍵結分析，利用恆電位/恆電流儀和紫外光/可見光光譜儀同步量測進行定性與定量分析，量測薄膜之電化學行為、著/去色應答時間、著/去色吸收光譜、穿透度調幅以及著色效率。利用電化學阻抗分析估算各介面之阻抗，進而得知鋰離子於三氧化鎢薄膜中的擴散係數。推論氧化矽在系統中可抑制三氧化鎢晶型的生成。W:Si=90:10莫耳比之三氧化鎢/氧化矽複合薄膜擁有較佳穿透度差值(ΔT = 59.49% @ 550 nm)，於550 nm波長之著色/去色應答時間為9.0 s/1.9 s；經過階梯電位100次切換後，穩定性最高，ΔA100/ΔA1比值達79.93%，遠高於純三氧化鎢薄膜的40.15%；且該樣品經階梯電位100次切換後，著色效率由30.88cm2/C提升至44.36cm2/C，吸收度差值ΔA保有0.394；由電化學阻抗分析得知其擴散係數為4.90×〖10〗^(-11)cm2/s。

關鍵字

四乙氧基矽烷；三氧化鎢；氧化矽；電致色變

並列摘要

A sol-gel derived peroxotungstic acid (PTA) sol has been employed for the deposition of tungsten trioxide-silica nanocomposite (WO3-SiOx) thin films and pure tungsten trioxide (WO3) thin films on fluorine doped-tin oxide (FTO) conductive glass by spin coating technique. As changing the molar ratio of W to Si, we can observe different properties. By using scanning electron microscopy (SEM) and X-ray diffraction (XRD), we can know micro-structure and crystalline structure of composite films respectively. In electrochemistry aspect, using Potentiostat/Galvanostat to get response time, stability and quantity, and using electrochemical impedance spectroscopy (EIS) to get the information of the diffusion of lithium. And optical properties observed by UV/Visible, like overall wavelength scanning and transmittance spectrum. Besides, we find the optimum component for the ratio of W to Si. 　　The results show that when the molar ratio of W to Ti is 90 to 10 (WSi-10), the film has uniform and transparent surface and the structure reveals amorphous phase. There is the best electrochemical stability and transmittance modulation (△T = 59.49% @ 550 nm) in this condition. At 550nm irradiation, the coloring and bleaching time of the film are 9.0 s and 1.9 s. The stability experiment shown that after switching 100 times of potential steps, the ratio of ΔA100/ΔA1 is 79.93% higher than WO3 thin film. By using ZView software to fit the EIS data, the diffusion coefficient of the film is 4.90×〖10〗^(-11)cm2/s.

並列關鍵字

tungsten trioxide ； silica ； composite films ； electrochromic

參考文獻

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三氧化鎢/氧化矽複合薄膜之製備與其電化學與電致色變性質之研究

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