In situ fabrication of ZnO nanorods/Ag hybrid film with high mid-infrared reflectance for applications in energy efficient windows

Abstract Energy efficient windows are playing an important role in view of the fabrication of Energy-Saving and Eco-Friendly devices which show high energy efficiency among energy conservation buildings. In order to modulate middle-far range infrared radiation, a new strategy based on modulating semiconducting oxides ordered array structure and coating of metal element was proposed for energy efficient windows. In this work, ZnO nanorods/Ag hybrid film with high transmittance in visible region and high reflectance in mid-infrared region was prepared via hydrothermal method and silver-mirror coating above quartz glass that has great potential application in energy efficient windows for infrared radiation cooling. In detail, ZnO nanorods arrays were prepared via in situ fabrication with spin-coating method and hydrothermal process at low temperature. While Ag nanoparticles were coated on as-prepared ZnO nanorods via a silver-mirror method which is also in line with the concept of energy conservation. According to characterization results, ZnO nanorods were grown along the wurtzite c axis perpendicular to the quartz substrate, and Ag nanoparticles were coated on ZnO nanorods with a tight interrelation. ZnO nanorods/Ag hybrid film showed high transmittance of 62% in the visible region and high reflectance above 90% in the mid-infrared region. Therefore, ZnO nanorods/Ag hybrid film obtained in this work indicates excellent optical performance in visible transmission and mid-infrared reflection, and this hybrid film is illustrated to be good candidates for saving energy in the field of energy efficient windows.