Preparation and Luminescence Properties of Ba5Si8O21 Long Persistent Phosphors Doped with Rare-Earth Elements

Abstract

The phosphors of formula Ba5Si8O21:Eu2+,Dy3+ were synthesized and studied in order to improve their properties. Their synthesis conditions were evaluated as a function of precursors, crucible composition, flux agents, dopants and temperatures. The samples were characterised by means of a systematic investigation through elemental, kinetic, mineralogical (both qualitative and quantitative), and morphological analysis. This study allows for a careful evaluation of the parameters that influence the formation and properties of Ba5Si8O21:Eu2+,Dy3+ phosphors. As for the synthesis conditions, the use of Na2SiO3, BaCO3 and NH4Cl as precursors was very important to reduce the temperature and time of synthesis. The reducing atmosphere produced with purified coal was cheaper and gave results similar to the more traditional gas mixture (H2/N2). At the end of this study, a phosphor with improved long persistent phosphorescence (LPP) characteristics was obtained with Ba/Si = 0.7, Eu/Si = 2.8 × 10−3 and Dy/Si = 3.6 × 10−3 following a 6 h-synthesis in a quartz crucible.

Recent progress on lanthanide-based long persistent phosphors: an overview

“…For example, 900 °C for Ca 2 BO 3 Cl: Eu 2+ ,Dy 3+ ; 28 and 1100–1250 °C for Ba 5 Si 8 O 21 :Eu 2+ ,Dy 3+ . 29 These high temperatures are attained in muffle furnaces and tube furnaces. Some of these furnaces, especially tube furnaces, coupled with appropriate control systems and gas (hydrogen, nitrogen, oxygen) connections are equipped to control the reaction conditions when an inert, reducing or oxidising atmosphere is needed.…”

Luminescent Complexes of Co(II), Ni(II), Cu(II), Zn(II)and Bi(III) with 2-Aminothiazole based Ligand and their Biological Studies

“…Apart from the medicinal applications, thiazole derivatives such as 4-hydroxythiazole [7], 4-ethoxy-1,3-thiazole [8] and various other derivatives such as coumarin thiazole hybrid [9,10], have been extensively studied for their luminescence properties [8,11]. Study of luminescence properties has been ever growing due to the immense applications of materials possessing this particular property [12]. This property is applicable for the production of Solid-state lighting, light-emitting diodes, instrument display, night-vision devices, tunable solid state lasers, and biological imaging for the detection of protein [10,11].…”