Preparation And Characterization Of NbSiN/Ag/Cu Low-emissivity Film

Low-E glass shows high transparency in the visible range of the spectrum and high reflectance of solar infrared radiation owing to its excellent spectral selectivity. Then the eco-friendly and energy-efficient low-emissivity films are becoming important currently. Silver is widely used as the reflectance layer due to its good electrical and optical properties. However, ultrathin Ag films are not well adherent on the substrates, high inter-diffusion, and easily agglomerated, leading to a degradation of the optical and electrical properties. In this study, an excellent low-emissivity films were prepared by radio frequency reactive magnetron sputtering on glass substrates. And the visible light transmittance, infrared reflectivity, surface roughness, sheet resistance, surface morphology and the corrosion resistance of low-emissivity films were studied systematically.In the experiment, four targets of Ag, Cu, Si and Nb were used, the argon and nitrogen were added as working gas and reactive gas. The performances of the film system were characterized by UV-Vi S spectrophotometer, Fourier-transform infrared spectroscopy, Surface Profilometer, four-point probe meter, dual beam focused ion beam-scanning electron microscope, and electrochemical workstation.Cuprum is used as the bottom dielectric layer because of its wetting property against silver. The sheet resistance has been reduced from 5.2Ω/□ to 4.1Ω/□, and the surface roughness also has been reduced to 1.12 nm compared to 2.35 nm without the seed layer when the sputtering power was 80 W, work pressure was 0.2 Pa, the argon flow rate was 15 sccm, target-substrate separation was 60 mm, sputtering time was 10 s, the film thickness was 2 nm, which is because C u has good thermal stability and can improve the density and smoothness. Nb Si N is added as the outer dielectric layer on account of its protective and antireflective performance. When silicon target power was 100 W, niobium target power was 50 w, argon flow was 40 sccm, nitrogen flow was 30 sccm, sputtering time was 90 min and pressure in vacuum was chamber 0.8 Pa, the visible light transmittance of Nb Si N film could reach up to 91.12% at the wavelength of 550 nm and the film roughness could reduce to 3.52 nm.The results exhibited that the Nb Si N/Ag/Cu low-emissivity films exhibit a high visible light transmittance(T%=83.9%, λ=550nm) and high infrared reflectivity(R%=95.3% in the 2.5μm~25μm range), which showed that the Low-E film has both daylighting property and energy saving.