A carbon-free sol–gel method for preparation of Lu3Al5O12: Ce3+ phosphors for potential applications in laser scintillators and LEDs

• Hydroxides of aluminum were firstly used as gelling agent to prepare LuAG: Ce3+ phosphors.
• Both nano and micron scale products can be obtained and they are suitable for the fabrication of laser scintillators and white light emitting diodes, respectively.
• Dispersion and crystallinity can be improved by using the two-step process.

Ce3+-doped lutetium aluminum garnet (LuAG) phosphors have been successfully synthesized by a facile carbon-free sol–gel method without using any organic gelling agent. Phase transitions from gel to LuAG were well investigated by X-ray diffraction and thermal analysis. The results confirmed that a pure LuAG phase can form at around 920 °C by directly crystallizing from amorphous material. Particle size of the LuAG phosphor can be controlled by adjusting the heat treatment process; therefore, both nano and micron-scale products can be obtained and they are suitable for the fabrication of laser scintillators and white light emitting diodes, respectively. Agglomeration can be observed in the nano-sized phosphor. For the micron-sized LuAG, a two-step process was used to avoid hard agglomeration. Particles of the obtained micron-sized phosphor are uniform and well-dispersed. Luminescence properties of the phosphors were characterized. Relative intensity of the micron-sized product is comparable with commercial phosphor.