Facile synthesis of YAG:Ce3+ thick films for phosphor converted white light emitting diodes

A crucial barrier in the development of YAG:Ce3+ phosphor films in the application for phosphors converted white light emitting diodes (pc-WLEDs) is to prepare the films, which are thick enough to provide considerable optical performance for matching the optical properties of the blue light chip. To overcome this barrier, this study reports a novel sol–gel method that takes advantage of the combustion pyrolysis process with glycine and urea as fuel. Transparent luminescent YAG:Ce3+ phosphor film with a thickness of 5.1 μm and homogeneous grain size of 60 nm was obtained on quartz substrate. The as-synthesized YAG:Ce3+ phosphor films have a quantum yield of 56% at 457 nm excitation. The YAG:Ce3+ phosphor films incorporated into pc-WLED were shown to have a slightly lower luminous efficacy of 82 lm/W, but a warmer correlated colour temperature of 4536 K as well as a higher colour rendering index of 75.8.