Abstract Vanadium pentoxide (V2O5) based electrochromic devices (ECD) are remarkable for their electropolychromism owing to adjacent multiple oxidation states of the material in the energy space. V2O5 also exhibits high theoretical capacitance, therefore have excellent potential to be exploited in various multifunctional devices; although their practicality suffers from the poor electrochemical stability of the material. Herein, we report active electrodes fabricated by overcoating hydrated-V2O5 (HVO) films with a thin layer of PEDOT:PSS. The ECDs with thinner HVO coatings showed multiple color switching representing V5+(orange/yellow), intermediate (green) and V4+ (blue) states while only partial reduction of V5+ ⬄ intermediate states could be resolved for the uncoated HVO. In addition, we observed no degradations in cyclic stabilities for the bilayered devices (measured for 1000 cycles) compared to a huge ∼70% transmittance contrast compromise for the bare HVOs. ECDs with thicker V2O5 coatings offered improved individual color intensities and ∼44% contrast retention. The differences in the electrochemical response was investigated by impedance studies that revealed a decoupling of the responses between the individual layers for the thicker variant.

中文翻译：

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由水合五氧化二钒和 PEDOT:PSS 涂层的双层组件制造的全固体电致变色器件的研究

摘要 基于五氧化二钒 (V2O5) 的电致变色器件 (ECD) 由于材料在能量空间中的相邻多个氧化态而具有显着的电多色性。V2O5 还具有很高的理论电容，因此在各种多功能器件中具有很好的开发潜力；尽管它们的实用性受到材料电化学稳定性差的影响。在此，我们报告了通过用薄层 PEDOT:PSS 覆盖水合 V2O5 (HVO) 薄膜制造的有源电极。具有较薄 HVO 涂层的 ECD 显示出多种颜色切换，代表 V5+（橙色/黄色）、中间（绿色）和 V4+（蓝色）状态，而对于未涂层的 HVO，只能解析 V5+⬄ 中间状态的部分减少。此外，我们观察到双层器件（测量 1000 次循环）的循环稳定性没有下降，而裸 HVO 的透射率对比度降低了 70%。具有较厚 V2O5 涂层的 ECD 提供了改进的单个颜色强度和约 44% 的对比度保留。通过阻抗研究研究了电化学响应的差异，该研究揭示了较厚变体的各个层之间的响应解耦。