結合溶膠凝膠法及網印法製作電致色變氧化鎢薄膜之研究

Abstract

本研究以溶膠凝膠法及網版印刷氧化鎢電致色變層，應用於電致色變元件。本實驗分三部份進行，第一部份為製作出乙醯過氧鎢酸粉末，並量測粉末性質。由熱差示分析，粉末在430℃位置有放熱峰，經XRD分析此放熱峰為氧化鎢薄膜結晶產生，為三斜結構的結晶相，氧化鎢薄膜250℃以下為非晶結構。第二部份調配不同氧化鎢溶膠溶液，並以旋轉塗佈法製作出氧化鎢薄膜。溶膠凝膠法所製備氧化鎢薄膜，分別給予未退火、250℃、450℃退火，光穿透率在560nm波段分別為ΔT=39%、36%與10%，隨退火溫度上升，穿透率下降，這是因為氧化鎢晶粒會慢慢團聚，造成電致色變性質降低。添加4 wt.%二水草酸氧化鎢薄膜，由可以有效抑制退火造成團聚現象，在未退火、250℃、450℃退火，光穿透率在560nm分別為ΔT=53%、34%與32%。 第三部份調配不同比例乙醯過氧鎢酸粉末與酒精，分別3:7、4:6與5:5，再將4wt.%乙基纖維素與二水草酸添加於氧化鎢溶膠凝溶液中，製作出網版印刷漿料，藉由網版印刷於出氧化鎢電致色變層，其光穿透率在560nm波段分別為ΔT=16%、36%與10%，4:6比例擁有最佳電致色變性質與光學性質。This study combines sol-gel method and screen-printing technology to fabricate tungsten oxide film which applied to electrochromic element.My study can be divided into three parts.First is fabricating APTA powder and then measure its properties.The APTA powder has exothermic peak at 430℃ by DSC analysis.We learned that exothermic peak is caused crystallization behaviors from WO3 film by XRD analysis.WO3 film is amorphous phase when temperature is lower than 250℃,then turns into monoclinc phase at 450℃. Secondly, a sol–gel derived APTA solution encompassing 0wt.% and 4 wt.% of oxalic acid dihydrate (OAD) has been employed for the deposition of tungsten oxide films by spin-coating technology. The transmittance modulation is 39% for films annealed at 100 ℃ and decreases to 36% and 10% for 250℃ and 450℃ annealing temperature for WO3 film with 0 wt.% OAD.Grain will aggregate with higher annealing temperature,and leads to dreasing of electrochromic properties. By adding 4wt.% OAD can efficiently keep grain from aggregate.Their transmittance modulation are 53%、34% and 32% for 100℃、250℃ and 450℃annealing temperature. The past prepared using Powder :EtOH formulations of 3:7、4:6 and 5:5,then adding 4wt.% ethyl cellulose and OAD. Their transmittance modulation are 53%、34% and 32% .The paste with a 4:6 ratio showed better electrochromic properties.