Yttrium hydroxide fluoride based monodisperse mesocrystals: additive-free synthesis, enhanced fluorescence properties, and potential applications in temperature sensing

Abstract

Pure and Eu³⁺-doped yttrium hydroxide fluoride (YHF) monodisperse mesocrystals were fabricated via an additive-free hydrothermal route. Each of the cantaloupe-like architectures is an assembly of aligned nanorod subunits in a side-by-side manner. The Eu³⁺-activated YHF mesocrystals exhibited higher red luminescence and improved efficiency compared to their microcrystal counterpart, which is believed to be ascribed to the combined effects, including high phase purity, well-defined facets, and highly uniform morphologies. Excellent accuracy in temperature determination by fluorescence measurements was achieved with this red-emitting mesocrystal, thus making it suitable for use as a luminescence-based thermometer.