All-Inorganic Multi-Color Converter Based on Eu3+-Doped Phosphor-in-Glass for White Light-Emitting Diodes

We proposed an all-inorganic multi-color converter based on Eu³⁺-doped phosphor-in-glass (PiG) for high-power white light-emitting diodes (WLEDs). The Eu³⁺-doped PiG was fabricated by screen-printing and low-temperature sintering a green phosphor into a Eu³⁺-doped glass matrix, which was prepared by a lead-free and low-melting glass frit doped with Eu³⁺ ions. When the Eu³⁺ doping content increases from 0.5 to 5 mol%, the transmittance of Eu³⁺-doped glass matrix is reduced while the red emission intensity is increased. In addition, with the green phosphor mass ratio of 30%, the Eu³⁺-doped PiG based WLEDs achieve a warm white light with a correlated color temperature (CCT) of 4496 K and a color rendering index (CRI) of 82 at the driving current of 350 mA. These results indicate that the Eu³⁺-doped PiG is a promising multi-color converter for high-power WLEDs.