Simultaneous control of size and exceptionally high PLQY in YAG:Ce nanophosphors

YAG:Ce nanophosphors are crucial for advanced micro-optoelectronic devices but are fundamentally constrained by the severe trade-off between size and photoluminescence quantum yield (PLQY). This limitation makes it challenging to prepare high-quality materials that meet both ultra-small size (< 50 nm) and high-PLQY requirements. In this study, YAG:Ce nanophosphors (< 50 nm) exhibiting a high PLQY of 64% were successfully prepared through a co-precipitation method guided by experimental design, representing a significant advance in the field. YAG:Ce nano transparent ceramic (Nano-TC) was fabricated via the high-pressure and low-temperature sintering (HPLT, 7.7 GPa and 150 ℃). The Nano-TC shows an integrated performance of ∼50% PLQY, 65.04% transmittance at 750 nm, and a Vickers hardness of 18.59 GPa, representing a 47.31% improvement over the single crystal. This study demonstrates a viable pathway for fabricating nano-sized YAG:Ce phosphors that concurrently achieve miniaturization and extremely high PLQY, and establishes HPLT sintering as an effective route for translating these nanocrystals into high-performance Nano-TC for next-generation lighting and display applications.