Low cost ZnO/CdO thin films effectively reduce blue light-induced damage to RPE cells by display and lighting devices

Abstract

High-energy, short-wavelength blue light emitted from display and lighting products, like TV, computer, mobile-phone and LED lighting can cause lots of hazards, especially for human retinal pigment epithelial (RPE) cells. Therefore, diminishing these blue hazards is always a must. In this study, ZnO/CdO (ZC) thin films capable of high-energy blue light shielding were developed. These thin films were deposited on glass substrate using an optimized sol-gel spin coating method with volume ratios of Zn:Cd ranging from 1:3 to 3:1. When the volume ratio of Zn:Cd is 3:5, the average transmittance of the blue light between 400 - 450 nm is 54.55%, and the transmittance of the center wavelength of 425 nm is 53.8%. At the same time, the average transmittance of visible light greater than 500 nm reached 91.2%. Finally, we attempted to verify the safety of ZC thin film with a 3:5 volume ratio of Zn:Cd (ZC-3) on RPE cells by using a blue light, the peak of which specifically appears at 425 nm. The changes of cell morphology result showed that the ZC thin films decreased the hazard of blue light on RPE cells.