Effect of adding Er3+ on the precipitated crystalline phase of SrF2–ZnO–B2O3 glass and upconversion luminescence

Abstract

Elucidating the relationship between nucleation and its structure in glasses is essential for the efficient development of new glass-ceramics. In this study, we developed new oxyfluoride nanocrystallized glass-ceramics with potential for upconversion luminescence, phosphor for LEDs, and fiber laser hosts. We investigated the glass-forming region in the SrF2–ZnO–B2O3 system and the crystallization behavior, glass structure, and optical properties of the xSrF2–(50−x)ZnO–50B2O3 system with the lowest quantity of glass-forming oxides. Whereas both the x = 10 and x = 20 samples precipitated more than 100 nm diameter of Zn4B6O13 by heat treatment, the Er3+-doped samples with x = 10 and x = 20 precipitated SrF2 nanocrystals of less than 20 nm. The resulting SrF2 nanocrystallized glass was transparent, and upconversion luminescence was observed by irradiating with a 980-nm LD. We found that the addition of Er3+ ions has a significant impact on crystallization, and the proposed mechanism for this is that the bond selectivity arising from the polarizability forms fluoride-rich domains, and Er3+ further assists the nucleation of SrF2 by serving as a crystal nucleation site. This study is expected to provide a guideline for the development of new transparent nanocrystallized glasses.