Infrared to visible upconversion luminescence in Ho3+ doped oxyfluoride glass ceramics

This article presents the upconversion luminescence from infrared to visible emission in Ho3+ ion doped oxyfluoride glass ceramics BaF2-B2O3-Al2O3 (BaAlBO3F2). A series of Ho3+ doped BaAlBO3F2 nanocrystals were introduced into the glassy phase using melt-quenching method followed by an appropriate heat treatment procedure. XRD confirms the crystalline phase in the glass ceramics. TEM indicates the nano-sized crystal in the glassy phase and the particle size is around 40 nm. EDAX confirmed the presence of doped Ho3+ ions in the glass. The photoluminescence spectrum of the prepared samples excited at 948 nm shows an intense red emission at 640 nm and green emission at 540 nm due to 5F5→5I8 and 5S2, 5F4→5I8 transitions of Ho3+ ions. The excellent upconversion of IR to visible (Red) properties of Ho3+ in glass ceramics have potential application in the field of solid-state upconversion lasers which operates in the visible range.