Hashemi Mahdieh, Gandomi Mona, Moradi Maryam, Ansari Narges
Department of Physics, College of Science, Fasa University Fasa 74617-81189 Iran
Department of Atomic and Molecular Physics, Faculty of Physics, Alzahra University Tehran 1993893973 Iran.
Nanoscale Adv. 2025 Jul 23. doi: 10.1039/d5na00584a.
Smart windows automatically adjust their properties to control infrared (IR) radiation which helps with saving energy by reducing the need for heating and cooling. In the current study, we use vanadium dioxide (VO), a phase change material that in temperatures above 68 °C behaves as a metal, to design smart windows. In its metallic phase, VO transmits less IR than would be expected from a smart window. Visible light transmission through the VO window in both its insulator and metallic phase is low which causes low indoor lighting. To solve this problem, we propose structuring the VO as a grating on a silica substrate. A thin film of VO blocks 62% of IR and transmits 46% of visible light, while a grating with an 800 nm period and 700 nm ribbon width improves IR blockage to 67%/63% and increases the visible light transmission to 53%/47% under transverse magnetic (TM)/electric (TE) radiation. Another issue of VO windows is the unpleasant yellow-brownish color of them. To solve this problem, we inserted atomic layers of Tungsten disulfide (WS) in the window structure. Adding 5 layers of WS keeps IR blockage and visible light transmission almost the same, while reducing transmission at the wavelength of 620 nm from 49%/41% in the case of VO grating, to 34%/30% under TM/TE radiation, which changes the window color. These window properties are consistent under different light angles. Notably, in the proposed VO-based smart windows, all three critical factors of visible light transmission, IR blockage, and pleasant window color are simultaneously optimized for an unpolarized incident light in a wide range of radiation angles. The simulated reported results of this paper pave a new way in the world of smart windows.
智能窗户会自动调节其特性以控制红外（IR）辐射，通过减少供暖和制冷需求来帮助节约能源。在当前的研究中，我们使用二氧化钒（VO），一种相变材料，在温度高于68°C时表现为金属，来设计智能窗户。在其金属相，VO传输的红外光比智能窗户预期的要少。在其绝缘体相和金属相，透过VO窗户的可见光传输率都很低，这导致室内采光不足。为了解决这个问题，我们提议将VO构造成二氧化硅衬底上的光栅。VO薄膜能阻挡62%的红外光并传输46%的可见光，而周期为800nm且带状宽度为700nm的光栅在横向磁（TM）/电（TE）辐射下将红外光阻挡率提高到67%/63%，并将可见光传输率提高到53%/47%。VO窗户的另一个问题是它们呈现出令人不悦的黄棕色。为了解决这个问题，我们在窗户结构中插入了二硫化钨（WS）原子层。添加5层WS能使红外光阻挡率和可见光传输率几乎保持不变，同时将620nm波长处的传输率从VO光栅情况下的49%/41%降低到TM/TE辐射下的34%/30%，这改变了窗户的颜色。这些窗户特性在不同光角度下是一致的。值得注意的是，在所提出的基于VO的智能窗户中，对于非偏振入射光在广泛的辐射角度范围内，可见光传输、红外光阻挡和宜人的窗户颜色这三个关键因素同时得到了优化。本文模拟报告的结果为智能窗户领域开辟了一条新道路。
