Crystal chemistry, luminescence and applications of Ce³⁺-doped garnets are reviewed and the tuning of optical properties is explainedviacombined insights from experiments and theory.

This review provides in-depth insight into the structure–luminescence–application relationship of 0D all-inorganic/organic–inorganic hybrid metal halide luminescent materials.

Near-infrared luminescent materials exhibit unique photophysical properties that make them crucial components in photonic, optoelectronic and biological applications. As broadband near infrared phosphors activated by transition metal elements are already widely reported, there is a challenge for next-generation materials discovery by introducing rare earth activators with 4f-5d transition. Here, we report an unprecedented phosphor K₃LuSi₂O₇:Eu²⁺ that gives an emission band centered at 740 nm with a full-width at half maximum of 160 nm upon 460 nm blue light excitation. Combined structural and spectral characterizations reveal a selective site occupation of divalent europium in LuO₆ and K2O₆ polyhedrons with small coordination numbers, leading to the unexpected near infrared emission. The fabricated phosphor-converted light-emitting diodes have great potential as a non-visible light source. Our work provides the design principle of near infrared emission in divalent europium-doped inorganic solid-state materials and could inspire future studies to further explore near-infrared light-emitting diodes.

The emerging new solid-state LED phosphors and the methodologies for their development have been reviewed in this perspective.