用于电致变色技术的氧化钨薄膜最佳厚度的探索

An Exploration of the Optimum Thickness of Tungsten Oxide Film for Electrochromic Technology

WO_(3)薄膜在小直流电压作用下,通过阳离子的嵌入/脱出可以在深蓝色和透明态之间进行可逆变色.注入离子的迁移路程(即薄膜厚度)对WO_(3)电致变色性能和循环稳定性有极大影响.因此,本文采用直流反应磁控溅射制备WO_(3)薄膜,通过控制溅射时间制备得到200 nm、500 nm、800 nm、1100 nm、1400 nm 5种厚度的薄膜样品,分别测试其初始态和1000圈CV循环后的电荷储量、调制率、响应时间及记忆时间,探究用于电致变色技术的WO_(3)薄膜的最佳厚度.结果表明,800 nm厚度的WO_(3)薄膜表现出的电致变色性能和循环稳定性明显优于其他厚度,在1000圈循环后电荷储量下降了25.1%,在波长550 nm处调制率衰减了1.59%,24 h静置后透过率增加了11.73%.该研究可为WO_(3)薄膜的产业化应用提供更为精确的理论指导.

WO_(3)films are reversibly color-changing between dark blue and transparent states by cations'intercalating/extracting under a small direct-current voltage.Thus,the migration distance of inserted cations(i.e.film thickness)has great influences on electrochromic properties and cyclic stability of WO_(3).In this study,WO_(3)films were prepared by DC reactive magnetron sputtering,and five thicknesses of 200nm,500nm,800nm,1100nm,and 1400nm were obtained by controlling the sputtering time.The charge storage,modulation rate,response time,and memory effect in the initial state and after 1000 CV cycles were recorded to investigate the optimal thickness of the WO_(3)films for electrochromic technology.The results show that the 800 nm-thick WO_(3)films exhibit significantly better electrochromic performances and cyclic stability than films of other thicknesses,after 1000 cycles,with a 25.1%decrease in charge storage,a 1.59%attenuation of modulation rate at a wavelength of 550nm,and a 11.73%increase in transmittance after 24h during memory-effect testing.This study can provide more precise theoretical guidance for the industrial application of WO_(3)thin films.