Enhanced high reflectance SiO2-Ag-SiO2 thin film adhesion for Concentrating Solar Power reflector

In this work, nanostructural Ag thin films and SiO2-Ag-SiO2 thin films were successfully fabricated on glass substrates by radio frequency (RF) magnetron sputtering for use in Concentrating Solar Power (CSP) reflectors. The XRD results showed that Ag thin films deposited under different powers had face-centered cubic structures with preferred orientation of (111). The Field emission scanning electron microscope (FESEM) results indicated a significant difference in the morphologies of Ag thin films. Also, increasing of power led to a correspondingly larger grain sizes from 8 to 25 nm. Film thickness tests showed that deposition rate changed almost linearly with increasing of power. The reflectance curves revealed that an amazing reflectance of SiO2-Ag-SiO2 thin films in near-infrared band can be obtained and it can be up to 99.97% . Most importantly, it is found that when SiO2 layer served as a medium layer, it can improve the film adhesion to a great degree, while it can served as a good protection layer with increasing reflectance when sputtered on the surface of Ag thin film.