β-NaYF₄:Yb³⁺/Er³⁺ nanocrystals embedded sol-gel glass ceramics for self-calibrated optical thermometry

β-NaYF₄:Yb³⁺/Er³⁺ nanocrystals embedded transparent glass ceramic has been successfully fabricated by direct incorporation of hydrophilic upconversion nanoparticles (UCNPs) into sol-gel silica glass and subsequent heat treatment. The temperature-sensitive upconversion luminescent behaviors of the as-fabricated UCNPs-silica glass ceramic are systemically investigated in order to investigate its potential application as luminescent thermometric medium. Impressively, benefiting from low-phonon-energy environment, highly UC emission for erbium ions in β-NaYF₄ nanophase and high transparency, good chemical/mechanical stability of the oxide glass matrix, the investigated glass ceramic has superiorities of high relative temperature sensitivity (~ 1.16% K⁻¹) and excellent thermal stability for accurate temperature sensing. This preliminary study not only provides a reference for fabricating other transparent bulk glass ceramics containing highly luminescent nanomaterials, but also exploits an effective approach for developing high-performance luminescent thermometers.