Rao Aiguo, Zhang Shiyu, Yang Mingqing, Wang Lei, Niu Chunhui, Fu Ming
Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing, 100044, P. R. China.
School of Instrument Science and Opto Electronics Engineering, Beijing Information Science and Technology University, Beijing, 100192, P. R. China.
Small. 2025 May;21(19):e2412644. doi: 10.1002/smll.202412644. Epub 2025 Mar 25.
Recently, various types of resonant cavities are widely fused with inorganic electrochromic material WO to compensate for its monotonous color modulation range. However, combining stabilized flexibility and vivid color performance in electrochromic devices is limited by the inherent brittleness and constrained transparency of commonly used top transparent electrodes, such as indium tin oxide (ITO). Herein, a novel top electrode-free structure of Cr/WO/Au metal-dielectric-metal (MDM) resonant cavity type flexible multicolor electrochromic device based on inner-layer porous Nylon 66 substrate is reported. By implementing a UV-cured gel electrolyte and PET thermoplastic sealing process, the electrochromic device exhibits ultra-flexibility, retaining 92.9% of its initial performance after 900 bending cycles at a radius of 4 mm, a wide color gamut spanning hues from violet to red, 40.59% maximum reflectance, and fast response times (t/t = 4.5 s/4.8 s). The porous MDM cavity generates a sharper scattered multi-beam interference resonance and provides a multi-path transport channel for ions, while the bottom porous Au reflection layer serves as the conductive electrode thus replacing the top transparent electrodes in traditional sandwich-like electrochromic device structure. Moreover, a large-area multipixel electrochromic array is further proposed to display different patterns, which demonstrates potential applications in future wearable electronic labels and smart camouflage.
最近，各种类型的谐振腔被广泛地与无机电致变色材料WO融合，以弥补其单调的颜色调制范围。然而，在电致变色器件中结合稳定的柔韧性和生动的色彩性能受到常用顶部透明电极（如氧化铟锡（ITO））固有脆性和有限透明度的限制。在此，报道了一种基于内层多孔尼龙66基板的新型无顶部电极结构的Cr/WO/Au金属-电介质-金属（MDM）谐振腔型柔性多色电致变色器件。通过采用紫外光固化凝胶电解质和PET热塑性密封工艺，该电致变色器件表现出超柔韧性，在半径为4毫米的情况下经过900次弯曲循环后仍保留其初始性能的92.9%，色域宽广，涵盖从紫色到红色的色调，最大反射率为40.59%，响应时间快（t/t = 4.5秒/4.8秒）。多孔MDM腔产生更尖锐的散射多光束干涉共振，并为离子提供多路径传输通道，而底部多孔金反射层充当导电电极，从而取代了传统三明治式电致变色器件结构中的顶部透明电极。此外，还进一步提出了大面积多像素电致变色阵列以显示不同图案，这展示了其在未来可穿戴电子标签和智能伪装方面的潜在应用。
