Infrared reflective properties of AZO/Ag/AZO trilayers prepared by RF magnetron sputtering

AZO/Ag/AZO trilayer films were prepared on glass substrates by radio frequency (RF) magnetron sputtering technology. Crystal structure, surface morphology, visible transmittance, and color scale of the AZO/Ag/AZO coated trilayers as functions of Ag and AZO layers thickness were investigated by X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Atomic Force Microscopy (AFM), optical transmittance spectra and CIELAB system. In addition, the electrical and infrared reflection properties of the coated trilayers were examined by four-point probe system and Fourier Transform Infrared Spectroscopy. The results indicated that the Ag inner layer started forming a continuous film at the thickness of 10 nm which was supported by XRD result of the distinct 200 and 220 Ag peaks. Besides, the highest average visible transmittance of 80.5% was obtained by the AZO (30 nm)/Ag (10 nm)/AZO (30 nm) structure. Furthermore, the lowest sheet resistivity of 4.36 Ω/sq and the highest infrared reflection rate of 96% in FIR region can be obtained by the AZO (30 nm)/Ag (13 nm)/AZO (30 nm) structure. The high infrared reflection property of the AZO/Ag/AZO trilayers makes it a promising candidate for energy conservation coatings.