Evolution of Strong Red Upconversion Luminescence in Er~(3+)-Containing Oxy-Fluoride Glass and Glass-Ceramics

摘要

The Er~(3+) concentration dependencies of upconversion luminescence in oxy-fluoride glass and glass-ceramics containing PbF_2 nanocrystals were investigated. Strong red emission from the ~4F_(9/2) → ~4I_(15/2) transition was observed with the addition of ～0.8 mol% Er~(3+) ions, whereas ～10 mol% of Er~(3+) is required to achieve such emission in several other crystalline hosts. Intensities of red emission further increased with the formation of nanocrystals through heat treatment. The Er~(3+) ions enriched in glass and segregated preferentially inside the PbF_2 nanocrystals that decreased the distance among Er~(3+) ions and thereby facilitated energy transfer.