電致色變材料運用相當廣泛，可以使用於建築節能窗戶來調節室內溫度。本研究採用反應性磁控濺鍍法沈積無機固態電解質氧化鉭薄膜，目的改善傳統的電致色變元件採用液態電解質會有液漏、裂解等問題，藉由改變製程參數氧氣流量(氧氣流量範圍為1~20sccm)與濺射功率(35~100W)，探討其對薄膜之成份、顯微結構、光學性質及電致色變性質的影響。

實驗結果顯示氧化鉭薄膜是非晶型且接近化學計量比的狀態，多孔性、鬆散的纖維狀結構，具有很高穿透率性質。隨著氧氣流量和功率增加，提高薄膜之折射率，降低薄膜電流密度及光學穿透度變化，顯示氧化鉭薄膜堆積密度提高，缺少多孔性之結構，不利於離子進出。當氧氣流量為3sccm與功率為50W時，在波長550nm處，其著色去色之穿透率變化可達56.7％，且其在任何波長下均具有較高的光學密度。比較Ta2O5/WO3薄膜與WO3薄膜電致色變性質，循環伏安曲線圖相近，顯示氧化鉭具有離子傳導的能力。實驗中將電致色變半元件膜進行可靠度測試，經過100次循環之後，其著去色穿透率改變不大及薄膜的穩定性仍相當良好。

最後將最佳參數之氧化鉭薄膜作為離子傳導層結合主要變色層氧化鎢及輔助變色層氧化鎳封裝做成一全固態電致色變元件，並量測其電致色變性質。其元件之組成結構Glass/ITO/WO3/Ta2O5/NiOx/ITO/Glass，施加電壓由±1V至±5V，著去色穿透率變化隨電壓增大而增加，其穿透率變化差異最高達到66.5%。

Recent years electrochromism have been extensively investigated due to their potential applications such as smart window of architecture to modulate the room’s temperature. In this study, inorganic-solid-state electrolyte tantalum oxide thin films were deposited by D.C. reactive magnetron sputtering in order to improve the leakage and deterioration of the traditional liquid electrolyte. The parameter of O2 atmospheres (the flow rate range : 1~20sccm) and powers (35~100W) were varied to investigate their effects on composition, microstructure, optical properties and electrochromic properties.

Experimental results indicated that tantalum oxide thin films were amorphous, near stoichiometric, porous with loose fibrous structure, and highly transparent in nature. As the oxygen flow rate and power increased, the refractive index increased however the current density and optical transmission change of the film decreased. It was showed that the Ta2O5 films with high packing density and low porous structure were unfavorable for ions transmission. At the oxygen flow rate of 3sccm and 50W, the transmission change between colored and bleached states at a wavelength of 550nm was 56.7%. The film has been observed with high optical density. Compared with Ta2O5/WO3 film and WO3 film, cyclic voltammetry curves were very close. It showed that tantalum oxide films had the capability of conducting ions. Assembled the electrochromic semi-device performsafter with 100 cycles test has good transmittance change and good quality stability.

Finally, Ta2O5 thin film with best electrochromic properties was used as a ion conducting layer to pack on the solid electrochromic device with electrochromic layer of WO3 and counter electrochromic layer of NiOx. Then the device was set to measure its electrochromic properties. The all solid electrochromic device was manufactured as the multilayer of Glass/ITO/WO3/Ta2O5/NiOx/ITO/Glass. Optical transmittance change of the device was increased by the applied voltage from ±1V to ±5V with transmission change of 66.5%.

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