Morphology-controlled hydrothermal synthesis and multifunctional luminescence properties of micro-crystals Gd6O5F8:Eu3+/Tb3+/Tm3+

Abstract

This paper reports on a facile hydrothermal route that has been developed to synthesize a precursor Gd(OH)_2.14F_0.86 and a novel phosphor host Gd₆O₅F₈. The morphology of the micro-sized Gd(OH)_2.14F_0.86/Gd₆O₅F₈ can be easily tuned in a controlled manner by altering the fluorine sources, alkali solutions, reaction time and the pH values of the initial solution. Under ultraviolet (UV) light, vacuum ultraviolet (VUV) light and low-voltage electron beam excitation, the Gd(OH)_2.14F_0.86/Gd₆O₅F₈:Ln³⁺ (Eu, Tb and Tm) samples show the characteristic f–f transitions of the Ln³⁺ ions and give bright red, green and blue emissions, respectively. The results prove that the as-synthesized Gd₆O₅F₈ are excellent host lattices for rare earth luminescence, which may find potential applications in solid-state light, field emission displays (FEDs).