Intrinsic blue-white luminescence, luminescence color tunability, synthesis, structure, and polymorphism of K3YSi2O7

Abstract

Two polymorphs of K₃YSi₂O₇, crystallizing in the space groups P6₃/mmc (1) and P6₃/mcm (2) can be synthesized by high temperature flux crystal growth. The flux growth conditions can be fine-tuned to yield a phase pure sample of polymorph (2), however, not of polymorph (1), which always co-crystallizes with polymorph (2). Polymorph (2) was found to exhibit intrinsic bluish-white light emission. Further studies determined that doping europium and dysprosium onto the yttrium site of this polymorph could readily tune the luminescence, with the purest white light emission found for the K₃YSi₂O₇: 10% Dy, 0.1% Eu composition (K₃Y_0.899Dy_0.1Eu_0.001Si₂O₇) (2-Dy,Eu).