为了得到能够呈现出合理电致变色性能的 Bi₂O₃ 薄膜, 需要筛选其膜厚. 通过磁控溅射法制备得到厚度为 20∼300 nm 的 Bi₂O₃ 薄膜, 并利用 UH4150 紫外可见 (ultraviolet-visible, UV-Vis) 分光光度计和 CHI-660e 电化学工作站测试薄膜的电致变色性能. 采用扫描电子显微镜 (scanning electron microscope, SEM) 和 X 射线衍射仪 (X-ray diffraction, XRD) 分别检测了薄膜的表面形貌和物相结构. 对变色对比度 (∆T_λ=550 nm)、电致变色效率 (η) 以及性能保留度 (R∆T 、R_η) 的表现进行综合甄别, 发现膜厚介于 60∼120 nm 之间的Bi₂O₃ 薄膜的 ∆T 和 η 分别达到 25% 和 10 cm²/C, 并且具有较高的电致变色性能保留度(R∆T = 20%、R_η = 44.6%). 这可能与该厚度区间薄膜的主要物相为具有较高离子导电性的δ 相有关.

It is necessary to select appropriate thickness for the fabrication of Bi₂O₃ thin films with reasonable electrochromic properties. Bi₂O₃ thin films with an approximate range of 20∼300 nm in thickness were prepared by magnetron sputtering. The electrochromic properties of the films were analyzed by using ultraviolet-visible (UV-Vis) spectrophotometry and an electrochemical workstation. The surface morphology and phase structure of the thin films were investigated by scanning electron microscope (SEM) and X-ray diffraction (XRD). After comprehensive screening to assess their performance in terms of the color change contrast (∆Tλ=550 nm), electrochromic efficiency (η), and performance retention (R∆T , R_η ), the values of ∆T and η of Bi₂O₃ thin films with a thickness between 60 nm and 120 nm were found to reach 25% and 10 cm²/C, respectively. Furthermore, the retention of the electrochromic properties (R∆T = 20%, R_η = 44.6%) is high. This may be related to the fact that the main phase of the film in this thickness range is δ, which is characterized by high ionic conductivity.