反射式電致色變元件之光學常數量測與對比度研究

Investigation of Optical Properties and Contrast Ratio of Reflective Electro-chromic Device

詹智超(Chih-chao Chan)

指導教授 ： 李正中

國立中央大學/理學院/光電科學研究所/碩士(2011年)

摘要

電致色變已被研究多年了，但其光學性質在著去色時的變化及狀況之探討並不多，因此進行WO3、Ta2O5、NiO的光學性質n (折射率)及k (消光係數)研究。本研究是以ITO導電玻璃為基板，利用電子槍蒸鍍WO3，以可見光–近紅外光光譜儀以及橢偏儀量測氧化鎢著色前後的狀況，得知氧化鎢著色前後的光學性質n(折射率)及k(消光係數)，工作氣壓為2×10-4 Torr時，其△T、△n及△k變化程度最為明顯。
以玻璃為基板，利用電子槍鍍製Ta2O5，考慮n(折射率)與透明度，因此選擇工作氣壓4×10-4Torr當作鍍製整個電致色變元件中離子傳輸層的參數，並利用可見光–近紅外光光譜儀以及橢偏儀量測，得知其光學性質n(折射率)及k(消光係數)。
以ITO導電玻璃為基板，利用電子槍蒸鍍NiO，以可見光–近紅外光光譜儀以及橢偏儀量測氧化鎳著色前後的狀況，得知NiO著色前後的光學性質n(折射率)及k(消光係數)，在鍍率為0.6~0.8 nm/s時，其△T、△n及△k變化程度最為明顯。
最後則是利用已知電致色變元件各層薄膜的光學常數：折射率(n)與吸收系數(k)，設計出讓電致色變反射式元件在著色狀態能夠達到可見光幾乎無反射的狀態，著去色時的平均反射率之差可高達40%，作為反射式的顯示器時可提高其對比度，達到CR≒21，也提高後視鏡防眩光的效果；最後嘗試以目前所知的光學常數設計出具有色彩變化的電致色變元件。

關鍵字

反射式電致色變元件 ； 對比度 ； 氧化鎳 ； 光學常數 ； 三氧化鎢 ； 電致色變

並列摘要

Electro-chromic device (ECD) has been investigated for many years, but there are few studies on optical properties of ECD between bleached/colored states. Therefore, the refractive indices and extinction coefficients of WO3, Ta2O5 and NiO were measured respectively in the experiment.
The thin films of WO3 were deposited on ITO coated B270 glass substrates by electron beam gun evaporation and the optical properties were measured by visible near-infrared spectrometry and spectrophotometer. The biggest difference of △T,△n and △k was found at oxygen pressure of 2×10-4 Torr.
The thin films of Ta2O5 were deposited on B270 glass substrates by electron beam gun evaporation and the optical properties were measured by visible near-infrared spectrometry and spectrophotometer. Considering the refractive index and transparency, the ion conductor, Ta2O5, of ECD were deposited at oxygen pressure of 4×10-4 Torr.
The thin films of NiO were deposited on ITO coated B270 glass substrates by electron beam gun evaporation and the optical properties were measured by visible near-infrared spectrometry and spectrophotometer. The biggest difference of △T,△n and △k was found at rate of 0.6-0.8 nm/s.
This is study adopted the refractive index and extinction coefficient of WO3, Ta2O5 and NiO which were measured as above mentioned procedures to design nearly zero reflectance of ECD in colored state. The difference of average reflectance reached 40% in bleached/colored state to raise contrast ration of reflective display to 21. In addition, this is designed various color of ECD based on optical properties measured.

並列關鍵字

Contrast Ratio ； Optical Properties ； NiO ； WO3 ； Reflective Electro-chromic Device

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