ZnO-Ag/SiO₂ blue light blocking films prepared at relatively low temperature

With the increasing application of display and illumination devices, the injury of blue light to human eyes have attracted more and more attention. The current absorptive anti-blue light films require high preparation temperatures. This study prepared ZnO-Ag nanofilms by sol–gel method at relatively low temperature, 250 °C. The films were further enhanced with SiO₂ protective layer under 200 °C to improve the mechanical properties and stability, and the transmittance was investigated. The results showed that the films blocked 50.4% of blue light at wavelengths of 415–455 nm while maintained an impressive average transmittance of 98% for visible light in the range of 500–800 nm. The films had no visual effect on the display quality and the color rendering index increased only from 80.3 to 83.4, but it reduced 25% of blue light-weighted irradiance. Additionally, the films exhibited a high stability when exposed to a high temperature and humid environment (85 °C and 85% RH). Rubbing with a Teflon ball at a load of 0.5 N and a linear speed of 80 mm/min for 30 min did not show significant damage. Finally, the damage to epithelial cells exposed to blue light in the presence of the developed film was greatly alleviated.