結合Lift-off及薄膜沈積技術製作固態電致色變影像顯示元件

Fabrication of Solid-State Electrochromic Display Devices by Combining Lift-Off and Thin Film Deposition Technology

程金保(Chin-Pao Cheng) ； 楊啓榮(Chii-Rong Yang) ； 林雅慧(Ya-Hui Lin) ； 李宗恆(Chung-Heng Lee) ； 倪茂倫(Mao-Lun Ni)

《技術學刊》 24卷3期 (2009/09) Pp. 175-182

https://doi.org/10.29507/JT.200909.0002

摘要

本專題主要重點在開發一雙面變色的電致色變系統，使元件中有兩層電致變色層，可透過反覆切換正負電壓，來顯示出這兩層薄膜中不同的圖案。元件之影像圖案係利用lift-off製程在ITO玻璃上來產生，並成長氧化鎢薄膜，以固態封裝方式製作一低耗能之電致色變影像顯示元件，極小的驅動電壓即可呈現影像。在薄膜沈積技術上，本專題使用濺鍍法與溶膠凝膠法分別沈積氧化鎢薄膜，並比較其特性與薄膜在著色態與去色態時之穿透率變化(ΔT)，選擇具有較佳視覺對比的薄膜沈積技術來製作本專題的影像顯示元件。製作完成之元件在驅動電壓±3V時之著色響應時間爲3.87秒、去色爲2.86秒，同時並利用拉曼光譜分析來探討氧化鎢電致色變薄膜之變色機制。此外，本專題製作的影像顯示元件，其操作電壓範圍在-4V至+4V間，可透過調整驅動電壓大小來改變顏色的深淺，提高元件的視覺對比。再者，此元件亦可製作在PET軟性基板上，達到可撓式之功能。未來期望能透過曝光顯影製程道數的增加及電路的設計與控制來提高影像的複雜度與多樣性。

關鍵字

電致色變 ； 氧化鎢薄膜 ； 濺鍍 ； 溶膠凝膠法 ； lift-off製程

並列摘要

This work has been concentrated on the fabrication of solid-state electrochromic display devices with double-sided electrochromic layers. The different images in the double-sided electrochromic layer can be revealed by applying positive and negative potential alternately. The specific patterns of the display were made on ITO glass by the lift-off process. And the tungsten oxide electrochromic layers of the display were prepared by RF sputtering because it can provide better electrochromic properties than sol-gel process. A reversible color change between blue and colorless was observed when appropriate positive and negative voltage were applied alternately to the electrochromic display device. The tungsten oxide electrochromic film has short bleach-coloration transition time when applying appropriate voltage of-3V/+3V. Switch-ing the colour takes about 3.87 seconds while the associated memory time is several hours. Turning off the colour takes about 2.86 seconds. The color depth of electrochromic film can be controlled by adjusting the magnitude of driving voltage. Furthermore, monitoring the changes in Raman spectra of the electrochromic films with bleach-coloration states enables the discussion of the mechanism of colouration. Finally, the electrochromic layers can also be made on PET substrate to produce a flexible electrochromic display device. In the future, the multiplicity of images of the electrochromic display devices may be enhanced by improving lift-off process and designing circuit.

並列關鍵字

electrochromic display devices ； tungsten oxide thin film ； sputtering ； sol-gel process ； lift-off process