热蒸镀法制备WO_3薄膜及其电致变色性能

Preparation of tungsten trioxide film by thermal evaporation method and its electrochromic performance

采用热蒸镀法在氟掺杂的锡氧化物（fluorine-doped tin oxide，FTO）导电玻璃衬底上沉积了一层WO3薄膜，运用X线衍射（XRD）、扫描电子显微镜（SEM）和原子力显微镜（AFM）等手段对样品进行表征，并运用紫外-可见光谱法表征了薄膜样品的电致变色性能．结果表明，该氧化钨薄膜在外加电压作用下，从褪色态（＋0.9 V）到着色态（-2.0 V），颜色由淡蓝色变为不透明的深蓝色，光透过率（波长为632.8 nm）由～72％下降为～0％，光学调节幅度高达72％，光密度（optical density，OD）变化量达到3，着色/褪色响应速度分别为30/20 s，循环（-1.8 V/＋0.8 V）30周期后变色性能保持良好，综合性能优于目前文献报道．由于该法制备的氧化钨薄膜电致变色综合性能突出，特别是光密度变化量大，在变色玻璃、智能窗户等环保节能领域将有广泛的应用前景．

Tungsten trioxide film was deposited on fluorine-doped tin oxide （FTO）glass substrate by vacuum evaporation method.The X-Ray diffraction,scanning electron microscope and atomic force mi-croscope were employed to characterize the composition and surface morphology of the sample.The elec-trochromic properties were determined by ultra-violet and visible spectrum.The results showed the almost colorless film turned to deep blue when the voltage was transformed from ＋0.9 V to -2.0 V,the trans-mittance at 632.8 nm fell from ~72%to ~0%,which meant that the accommodation amplitude was a-bout 72%and the change of optical density （OD）was up to 3 .The film took 30 seconds to color and 20 seconds to fade.In 30 cylces of coloring/bleaching test at -1.8/＋0.8 V,the results indicated that the films presented a stable electrochromic properties.Because of the outstanding electrochromic properties, especially the change of optical density,our films should have broad applications in the field of environ-ment protection and energy-related products such as electrochromic glass and smart window.