“…In this work, we focused on the UC luminescence properties, mechanisms, and applications of germanate oxyfluoride glass ceramics (GCs) containing LaF 3 :Er 3+ nanocrystals upon simultaneous triwavelength NIR excitation. In most RE 3+ , Er 3+ is regarded as the most efficient ion for UC, which is attributed to its abundant energy cascades of 4f–4f transitions and larger NIR absorption cross section. , Compared to other UC materials, the GCs containing LaF 3 :Er 3+ nanocrystals possess the following advantages: lower phonon energy, higher chemical durability and mechanical strength, more intense UC luminescence, weaker light scattering, and better-matched refractive index. − Moreover, UC luminescence properties, mechanisms, and applications of the GCs upon simultaneous triwavelength excitation have rarely been reported to our knowledge. Here, we studied the UC luminescence properties of the germanate oxyfluoride GCs containing LaF 3 :Er 3+ nanocrystals upon simultaneous triwavelength NIR excitation.…”