Effect of magnetron sputtering power on the properties of the AlO _X monolayer and AlO _X /MgF₂ bilayer anti-reflection films

Abstract

The AlO X monolayer anti-reflection (MLAR) films and the AlO X /MgF2 bilayer anti-reflection (BLAR) films were deposited on high-purity glasses with magnetron sputtering. We investigated the influences of sputtering power on the O/Al molar ratio, microstructure, and optical properties of the AlO X MLAR films and AlO X /MgF2 BLAR films. The results showed that a too high or a too low sputtering power was detrimental to the preparation of the high-quality films, which could only be obtained when the sputtering power was 115 W. However, the sputtering power did not affect the crystallinity of the films, all of which were amorphous. When the sputtering power was 115 W, the high-purity AlO X MLAR film exhibited an O/Al molar ratio of 2.27:1, a refractive index of 1.426, and an average transmittance (T avg: average transmittance of the quartz glass deposited the film, hereinafter the same) of 94.03% within 300–1100 nm wavelength range. The T avg of AlO X /MgF2 BLAR film with a power of 115 W was 94.99%, which was 1.92% higher than that of the glass substrate. And it improved the cell’s photoelectric conversion efficiency (PCE) by 3.19%.