Interface reaction-induced fabrication of RE3Al5O12 (RE = Gd–Lu, Y) phosphor conversion plates for WLEDs
Abstract
Rare earth aluminate garnets (RE3Al5O12, REAGs) have important application values in optical fields owing to their exceptional luminescence properties, chemical stability, and thermal stability. These materials typically require thin-film configurations for applications such as solid-state lighting (phosphor-converted white LEDs), radiation detection scintillators, and laser gain media. In this study, we developed a hydrothermal reaction strategy to prepare rare earth hydroxycarbonate films (RE2(OH)x(CO3)y(NO3)(6−x−2y)·nH2O, RE = Tb–Lu, Y) on sapphire substrates using rare earth nitrates and urea. Subsequent thermal treatment induced interfacial reactions, enabling the fabrication of broad-spectrum REAG (RE = Gd–Lu, Y) systems. We systematically investigated the luminescence characteristics of the REAG (RE = Tb, Y, Lu) systems. By integrating LuAG, YAG, and TbAG films with a blue LED chip, we achieved cold white light emission with a color rendering index (CRI) of Ra = 70.3. This research provides a novel approach for preparing rare earth garnet films and demonstrates their application potential in solid-state lighting.