Jiang Cancheng, He Lanyue, Xuan Qingdong, Liao Yuan, Dai Jian-Guo, Lei Dangyuan
Department of Materials Science and Engineering, Centre for Functional Photonics, and Hong Kong Branch of National Precious Metals Material Engineering Research Centre, City University of Hong Kong, Kowloon, Hong Kong, 999077, China.
Department of Refrigeration and Cryogenics Engineering, Hefei University of Technology, 193 Tunxi Road, Hefei, 230009, China.
Light Sci Appl. 2024 Sep 18;13(1):255. doi: 10.1038/s41377-024-01560-9.
Thermochromic coatings hold promise in reducing building energy consumption by dynamically regulating the heat gain of windows, which are often regarded as less energy-efficient components, across different seasons. Vanadium dioxide (VO) stands out as a versatile thermochromic material for smart windows owing to its reversible metal-to-insulator transition (MIT) alongside correlated structural and optical properties. In this review, we delve into recent advancements in the phase-change VO-based thermochromic coatings for smart windows, spanning from the macroscopic crystal level to the microscopic structural level (including elemental doping and micro/nano-engineering), as well as advances in controllable fabrication. It is notable that hybridizing functional elements/materials (e.g., W, Mo/SiO, TiN) with VO in delicate structural designs (e.g., core-shell, optical cavity) brings new degrees of freedom for controlling the thermochromic properties, including the MIT temperature, luminous transmittance, solar-energy modulation ability and building-relevant multi-functionality. Additionally, we provide an overview of alternative chromogenic materials that could potentially complement or surpass the intrinsic limitations of VO. By examining the landscape of emerging materials, we aim to broaden the scope of possibilities for smart window technologies. We also offer insights into the current challenges and prospects of VO-based thermochromic smart windows, presenting a roadmap for advancing this field towards enhanced energy efficiency and sustainable building design. In summary, this review innovatively categorizes doping strategies and corresponding effects of VO, underscores their crucial NIR-energy modulation ability for smart windows, pioneers a theoretical analysis of inverse core-shell structures, prioritizes practical engineering strategies for solar modulation in VO films, and summarizes complementary chromogenic materials, thus ultimately advancing VO-based smart window technologies with a fresh perspective.
热致变色涂层有望通过动态调节窗户的热量获取来降低建筑能耗，窗户通常被视为能源效率较低的部件，且这种调节作用贯穿不同季节。二氧化钒（VO）因其可逆的金属-绝缘体转变（MIT）以及相关的结构和光学特性，成为智能窗户领域一种多功能的热致变色材料。在本综述中，我们深入探讨了用于智能窗户的基于VO相变的热致变色涂层的最新进展，涵盖从宏观晶体水平到微观结构水平（包括元素掺杂和微/纳米工程），以及可控制备方面的进展。值得注意的是，在精细的结构设计（如核壳结构、光学腔）中将功能元素/材料（如W、Mo/SiO、TiN）与VO进行复合，为控制热致变色性能带来了新的自由度，包括MIT温度、透光率、太阳能调制能力以及与建筑相关的多功能性。此外，我们还概述了可能补充或超越VO固有局限性的替代发色材料。通过审视新兴材料的前景，我们旨在拓宽智能窗户技术的可能性范围。我们还深入探讨了基于VO的热致变色智能窗户当前面临的挑战和前景，为推动该领域朝着提高能源效率和可持续建筑设计方向发展提供了路线图。总之，本综述创新性地对VO的掺杂策略及其相应效果进行了分类，强调了它们对智能窗户至关重要的近红外能量调制能力，开创了对反核壳结构的理论分析，优先考虑了VO薄膜中太阳能调制的实际工程策略，并总结了互补发色材料，从而最终以全新视角推动基于VO的智能窗户技术发展。
