旋涂法制备WO3薄膜电致变色性能

"智能窗"大规模推广顺应可持续发展潮流,三氧化钨(WO_3)是生产"智能窗"的一种重要电致变色材料,但调控WO_3薄膜电致变色性能机制仍待进一步研究。采用旋涂法制备WO_3薄膜,重点研究了溶液浓度和旋涂次数对调控WO_3薄膜电致变色性能的影响。通过表面轮廓仪测量薄膜厚度,X射线衍射(XRD)测量薄膜结晶情况,原子力显微镜(AFM)和扫描电子显微镜(SEM)分析薄膜表面形貌,光谱仪测量薄膜初始态、着色态和褪色态的透射率。实验结果表明,随着溶液浓度增加(0. 2～1. 0 mol/L),薄膜厚度从9. 7 nm增加到33. 3 nm,透射率调制能力从0%提升到37. 0%;多次旋涂薄膜厚度线性增长,线性拟合优度(R~2)达0. 98,5次旋涂后透射率调制能力达51. 3%。改变溶液浓度和旋涂次数都是调控薄膜透射率调制能力的有效手段,精准调控薄膜透射率调制能力对设计不同应用场景的电致变色器件具有重大意义。

Electrochromic Properties of WO3 Film by Spin-coating

Large-scale promotion of "smart windows" is to conform to the trend of sustainable development. Tungsten trioxide(WO₃) is an important electrochromic material for producing "smart window" but the mechanism of regulating the electrochromic properties of WO₃ thin films remains to be further studied. WO₃ films were prepared by spin-coating process. The thickness of films was measured by surface profiler. The crystallinity of films was measured by X-ray diffraction(XRD) and the surface morphology was measured by atomic force microscope(AFM) and scanning electron microscope(SEM). Finally, the transmittance of the films was measured by spectrometer. The experiment results indicated that the thickness of the films increased from 9.7 nm to 33.3 nm with the solution concentration increasing(0.2 mol/L to 1.0 mol/L), and the transmittance modulation capability of this film increased from 0% to 37.0%. The thickness of multiple spin-coated films increased linearly, and goodness of fit(R²) was 0.98. After 5 times of spin-coating, the transmittance modulation capability reached 51.3%. Both changing the concentration of solution and the times of spin-coating are the effective means to regulate transmittance modulation capability and it is of great significance to accurately regulate the transmittance modulation capability of the film to design the electrochromic devices for different application scenarios.