Bright blue cooperative upconversion emission of Yb3+ from langbeinite K2Ti1.887 Yb0.113(PO4)3 single crystal

Abstract

Ytterbium doped langbeinite K2Ti1.887Yb0.113(PO4)3 (KTYP) single crystals were grown using high temperature molten salt flux growth method. Inclusion-free KTYP crystals with sizes up to 3×3×3mm3 were attained using K6P4O13 molten flux. The complete melting point of solute and solvent is above at 1223K. Langbeinite phase KTYP crystals are growing in higher concentration of Yb2O3 in flux solution. KTYP emits a strong cooperative blue emission centered at 488nm owing to Yb-Yb pairs under 980nm laser excitation. To the best of our knowledge, phosphate based langbeinite crystal found exhibit cooperative upconversion emission at ~488nm.