網印法製作氧化鎢膜應用於電致色變元件之研究

Abstract

電致色變係利用外加電場時，使材料產生著/去色變化，進而影響外來光線的穿透作用。此一特性可以被應用在汽車和建築物之玻璃上，以製作節省能源、可調節光線進入及控制熱負荷之智慧型窗戶。然而，目前製程技術通常為濺鍍法或蒸鍍法等，耗時且設備成本較高。本研究擬利用溶膠凝膠法來製備氧化鎢膠體，除了能控制微孔結構，在製備多成分系統也較簡易，並具有低成本的特點。在成膜製程方面，本作品將結合精密網版印刷技術，先在網版上製作出特殊設計之圖案，利用此一網版將氧化鎢膠體在ITO 玻璃上印出圖案之薄膜。此一製程快速、簡單易操作，以及成本低、製程溫度低、不需要真空環境、容易連續製程及在各種材料上大面積塗佈等優點。封裝成電致色變元件後，使節能窗更具備美觀及藝術欣賞之價值。技術重點包括網印漿料之調配、控制網版印刷機台製程之最佳條件、結合電解質封裝成電致色變元件及其性能分析等。未來將此一電致色變元件應用於玻璃窗，能兼顧採光與隔熱的需求，經由適當的設計，可以降低建築物的空調及照明等電力負荷，達成節能之目的。

Electrochromism is an important thin film technology currently used in the application of energy saving windows, which mainly utilizes the changes in the crystal lattice structure produced by the reduction or oxidization of transition metals oxide to form different colored/bleached states. One of its great characteristics is: EC coatings could bring a transparent glazing into a color-tinted glazing and then back to the original state when it is subjected to an on-off small voltage. This allows for the control of sunlight and heat entering through the windows to reduce the burden on air conditioning systems to achieve energy conservation. The WO3 thin films are prepared by the sol-gel method following the inorganic route. The precursor material will be analyzed by differential thermal analysis (DTA) and the structure will be assessed by XRD and FTIR. To make the coating gel, the based solid materials of precursor will be dissolved in isopropyl alcohol and critric acid will be used to as an organic ligand. The gel will be screen printed on ITO glass substrates to form WO3 thin films. Propylene carbonate (PC) is further mixed with LiClO4 for the preparation of electrolyte. After packaged into components, electric voltage is applied to the films to generate reduction or oxidization, which can obtain different colored/bleached states. Finally, the properties of the elcetrochromic devices, including optical density change, coloration efficiency, transmittance and specular reflectance will be analyzed and characterized by spectroscopy from ultraviolet to near infrared spectral region. Furthermore, Raman spectroscopy analysis is performed to get a greater understanding of electrochromic mechanisms. The device is expected that will reach to: low cost, no pollution, small, mass production and environmental protection. As a matter of fact, precision screen-printing technology has been paid attention by high-tech industries such as solar cell, LCD and optoelectronic recently due to that can simplify the steps of process remarkably and helpful to mass production.