CaAlSiN 3 :Eu 2+ -based color-converting coating application for white LEDs: Reduction of blue-light harm and enhancement of CRI value

Abstract In this paper, red color-converting coating on glass substrate is prepared by a simple spray painting method using CaAlSiN 3 :Eu 2+ red emitting phosphor and silica sol matrix for application in reducing the blue-light harm and enhancing the CRI value of white LEDs. Phosphors distribution in the coating is investigated by field emission scanning electron microscope (FE-SEM) and fluorescence microscope. Luminescent properties, especially for the blue-light leakage and the CRI value of the red color-converting coating coupled with a commercial white LED are demonstrated. The blue-light leakage decreases while the CRI value enhances when the prepared red color-converting coating was applied in commercial white LEDs. This study offers a facile route to reform the white LEDs for the purpose of reduction of blue-light harm and enhancement of CRI value.