The enhancement of thermal endurance in doped low emissive ZnO/Ag/ZnO multilayer thin film

Ag-based low emissive (low-E) film is the most popular material employed in energy saving field. However, thermal endurance of this film is seriously poor. Multivalent metal doping is proposed as an economical way to solve this problem. In this report, ZnO/Ag/ZnO and ZnO/(Cu/Al-doped) Ag/ZnO multilayer films are prepared on glass by sputtering technique. Rapid thermal annealing (RTA) is adopted to stabilize the film growth. Low-E related performance: electrical resistance, infrared (IR) reflectance and transmittance at visible light are checked for as-deposited and annealed films. SEM, AFM, TEM are further applied to inspect the morphology, structure feature and composition information of the films. It is discovered that either Cu or Al doping can effectively suppress 0 diffusing into Ag layer and prevent Ag being oxidized, thereby prohibit film deterioration and improve low-E performance during thermal annealing. Especially Al-doping shows prominent improvement of thermal endurance for full low-E performance. The most thermally endurable ZnO/(Al-doped)Ag/ZnO film in this work is of 30 at.% designed (corrected as similar to 12%) doping concentration, with the lowest sheet resistance of 3.388 Omega/square, highest visible light transmittance of 70.0% (at 550 nm) and IR reflectance of 90.6% (at 2500 nm) after 680 degrees C RTA treatment. (C) 2020 Elsevier B.V. All rights reserved.