{"title":"Transparent metafilms for enhanced thermal regulation in energy-efficient windows","authors":"Biyuan Wu, Yue Ren, Xiqiao Huang, Meijie Chen, Yong Li, Jiangtao Li, Yang Kou, Xiaohu Wu","doi":"10.1515/nanoph-2025-0351","DOIUrl":null,"url":null,"abstract":"Transparent metafilms with spectrally selective properties have shown great potential in energy-efficient window systems. Most previous studies focused on optimizing materials and thicknesses to enhance visible transmittance and near-infrared (NIR) reflectance. However, few have considered how the position of the metafilms on the glass affects overall optical and thermal performance, especially in the mid-infrared (MIR) range critical for radiative cooling. In this work, we propose and analyze a five-layer TiO<jats:sub>2</jats:sub>/Ag/TiO<jats:sub>2</jats:sub>/Ag/TiO<jats:sub>2</jats:sub> structure and systematically evaluate its performance under two typical installation scenarios. Numerical simulations based on the transfer matrix method show that both configurations maintain a high visible transmittance (∼0.88) and an effective NIR reflectance (∼0.98). Notably, a substantial difference is observed within the atmospheric transparency window 8–14 μm, where the interior-coated configuration possesses a high emissivity of 0.8. This value significantly exceeds the average emissivity of 0.01 found for the exterior-coated configuration, thereby resulting in superior passive radiative cooling capability. Moreover, we also compared the net radiative cooling power under the two configurations. These findings reveal that the position of the transparent metafilms critically influences MIR radiation. Coating placement on the interior surface not only maintains favorable solar modulation but also markedly enhances the thermal dissipation. This study offers theoretical guidance and practical insight into the design and implementation of metafilms in energy saving window systems aimed at reducing energy consumption, especially in regions with hot climates.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"15 1","pages":""},"PeriodicalIF":6.6000,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Nanophotonics","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1515/nanoph-2025-0351","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Transparent metafilms with spectrally selective properties have shown great potential in energy-efficient window systems. Most previous studies focused on optimizing materials and thicknesses to enhance visible transmittance and near-infrared (NIR) reflectance. However, few have considered how the position of the metafilms on the glass affects overall optical and thermal performance, especially in the mid-infrared (MIR) range critical for radiative cooling. In this work, we propose and analyze a five-layer TiO2/Ag/TiO2/Ag/TiO2 structure and systematically evaluate its performance under two typical installation scenarios. Numerical simulations based on the transfer matrix method show that both configurations maintain a high visible transmittance (∼0.88) and an effective NIR reflectance (∼0.98). Notably, a substantial difference is observed within the atmospheric transparency window 8–14 μm, where the interior-coated configuration possesses a high emissivity of 0.8. This value significantly exceeds the average emissivity of 0.01 found for the exterior-coated configuration, thereby resulting in superior passive radiative cooling capability. Moreover, we also compared the net radiative cooling power under the two configurations. These findings reveal that the position of the transparent metafilms critically influences MIR radiation. Coating placement on the interior surface not only maintains favorable solar modulation but also markedly enhances the thermal dissipation. This study offers theoretical guidance and practical insight into the design and implementation of metafilms in energy saving window systems aimed at reducing energy consumption, especially in regions with hot climates.
期刊介绍:
Nanophotonics, published in collaboration with Sciencewise, is a prestigious journal that showcases recent international research results, notable advancements in the field, and innovative applications. It is regarded as one of the leading publications in the realm of nanophotonics and encompasses a range of article types including research articles, selectively invited reviews, letters, and perspectives.
The journal specifically delves into the study of photon interaction with nano-structures, such as carbon nano-tubes, nano metal particles, nano crystals, semiconductor nano dots, photonic crystals, tissue, and DNA. It offers comprehensive coverage of the most up-to-date discoveries, making it an essential resource for physicists, engineers, and material scientists.