Abstract The phase transition temperature (~68 °C) of M-VO2 film can be lowered significantly by tungsten (W) doping into the crystal lattice of VO2 due to the reduction of the strength of V-V pair interaction. However, W doping was always coupled with a serious weakening of luminous transmittance and solar modulation efficiency because W dopants can increase the electron concentration of VO2 film. Herein, the simultaneous introduction of W dopants and mesopores into M-VO2 nanocrystals was employed to prepare VO2 film. Interestingly, the obtained 0.4 at% W-doped mesoporous VO2 nanocrystals based composite films exhibited enhanced comprehensive thermochromic performance with excellent solar modulation efficiency (ΔTsol = 11.4%), suitable luminous transmittance (Tlum = 61.6%) and low phase transition temperature around 43 °C, much lower than 65.3 °C of undoped VO2. It was demonstrated that the lower phase transition temperature of VO2 can be primarily attributed to abundant lattice distortion after W doping, whereas the mesoporous structure can facilitate the uniform distribution of W dopants in VO2 nanocrystals, enhance the luminous transmittance and guarantee enough VO2 nanocrystals in the composite film to keep relatively high solar modulation efficiency. Therefore, this work can provide a new way to balance the three important parameters for the thermochromic performance of VO2 film (ΔTsol, Tlum and Tc) and probably promote the application of VO2 nanocrystals in the energy efficient windows.

中文翻译：

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具有增强的综合热致变色性能的钨掺杂 M 相 VO2 介孔纳米晶体用于智能窗户

摘要 由于 VV 对相互作用强度的降低，将钨 (W) 掺杂到 VO2 的晶格中可以显着降低 M-VO2 薄膜的相变温度 (~68 °C)。然而，W掺杂总是伴随着透光率和太阳能调制效率的严重减弱，因为W掺杂可以增加VO2薄膜的电子浓度。在此，W 掺杂剂和介孔同时引入 M-VO2 纳米晶体被用来制备 VO2 薄膜。有趣的是，获得的 0.4 at% W 掺杂介孔 VO2 纳米晶基复合薄膜表现出增强的综合热致变色性能，具有优异的太阳能调制效率（ΔTsol = 11.4%）、合适的透光率（Tlum = 61.6%）和约 43°的低相变温度C，远低于65。3 °C 的未掺杂 VO2。结果表明，VO2 较低的相变温度主要归因于 W 掺杂后大量的晶格畸变，而介孔结构可以促进 W 掺杂剂在 VO2 纳米晶中的均匀分布，提高透光率并保证足够的 VO2 纳米晶在复合薄膜保持相对较高的太阳能调制效率。因此，这项工作可以为平衡VO2薄膜热致变色性能的三个重要参数（ΔTsol、Tlum和Tc）提供一种新方法，并可能促进VO2纳米晶体在节能窗中的应用。而介孔结构可以促进 W 掺杂剂在 VO2 纳米晶中的均匀分布，提高透光率并保证复合膜中有足够的 VO2 纳米晶以保持较高的太阳能调制效率。因此，这项工作可以为平衡VO2薄膜热致变色性能的三个重要参数（ΔTsol、Tlum和Tc）提供一种新方法，并可能促进VO2纳米晶体在节能窗中的应用。而介孔结构可以促进 W 掺杂剂在 VO2 纳米晶中的均匀分布，提高透光率并保证复合膜中有足够的 VO2 纳米晶以保持较高的太阳能调制效率。因此，这项工作可以为平衡VO2薄膜热致变色性能的三个重要参数（ΔTsol、Tlum和Tc）提供一种新方法，并可能促进VO2纳米晶体在节能窗中的应用。