Green-Emissive Carbon Dots with a High Quantum Yield Applied for Photoconversion Film to Prevent from Blue Light Damage

High-energy blue light is highly detrimental to health as it can penetrate the lens into the retina, potentially causing atrophy or even death of retinal pigment epithelial cells. To prevent the harmful effects of high-energy blue light on our health, here the preparation of a photoconversion film specifically designed to block high-energy blue light is reported, which is composed of green-emissive carbon dots (G-CDs) with a high photoluminescence quantum yield (PLQY = 95%) dispersed in polyvinyl alcohol (PVA) matrix. Notably, such a film (named as G-CDs@PVA) not only converts an incident laser light with a short wavelength into a fluorescence with a longer wavelength, but also exhibits concentration-dependent (0, 10, 20, and 30 wt.%) blue light barrier rate and green-emissive intensity. With the increase of the concentration of G-CDs in the film, the blue light barrier rate of the film as well as the maximum intensity of the green emission are also increased. When the concentration of G-CDs reaches 30 wt.%, the blue light barrier rate of G-CDs@PVA achieves up to 97%. Furthermore, G-CDs@PVA film is attached to a blue light-emitting diode (LED) chip to explore its practical application in the field of blocking blue light damage.