Spectrally selective TiO<inf>2</inf>/Ag/TiO<inf>2</inf>/(SiO<inf>2</inf>/TiO<inf>2</inf>)⁵ film for energy-efficient windows

Abstract

Summary form only given. Spectrally selective film with low emissivity has been attracting a great amount of research interest due to its extensive application in solar energy utilization, energy saving in buildings, etc.. Photonic band gap (PBG) structures, having the potential ability to control the propagation of electromagnetic waves, provide great opportunities for realizing good compatibility of low emissivity and high visible light transmission. In this work, a PBG structure of (SiO ₂ /TiO ₂ ) ⁵ with Ag system for weakening solar and thermal radiant energy was proposed theoretically and experimentally. As shown in Fig. 1, the designed TiO ₂ /Ag/TiO ₂ /(SiO ₂ /TiO ₂ ) ⁵ structure exhibits a superior performance with creatively as high reflectance as 74.2%, 80.8%, and 98.1% in the wavelength ranges of ultraviolet (0.28-0.4 μm), near infrared (0.8-2.15 μmm), and mid-far infrared (3-25 μmm), respectively. Meanwhile, the relatively low reflectance in visible region shows that the film has high visible transparence. Further numerical simulations demonstrate that the structure has the merit of wide-angle stable performance. This work provides a path towards realization for low emissivity energy-efficient film.