Sub‐5 nm Ln3+‐doped BaLuF5 Nanocrystals: A Platform to Realize Upconversion via Interparticle Energy Transfer (IPET)

Upconverting nanomaterials possess interesting optical characteristics, such as sharp emissions, and long luminescence life times, and exhibit multiple emissions spanning a wide region (UV to NIR), which are exploited in several applications like developing phosphors, biomarkers, and optoelectronic devices, to name only a few.