High‐Brightness LaPO₄:Ce³⁺, Tb³⁺ Nanophosphors: Reductive Hydrothermal Synthesis and Photoluminescent Properties

Abstract

This paper definitely reveals that LaPO 4 :Ce 31 , Tb 31 (LAP) nanophosphors prepared by normal hydrothermal method suffer significant loss of luminescence due to the oxidation of Ce 31 -Ce 41 at hydrothermal stage. To effectively protect Ce 31 from oxidation, a reductive hydrothermal process using hydrazine hydrate as a protecting agent is proposed to synthesize LAP nanophosphors with different Ce 31 and Tb 31 concentrations, which exhibited much stronger green photoluminescence (PL) and longer lifetime than the products prepared by normal hydrothermal method. Furthermore, the high-brightness LAP nanophosphors exhibited high-quenching concentration of Tb 31 ; the La 0.4 Ce 0.4 Tb 0.2 PO 4 nanophosphor showed almost the same PL intensity as that of the commercially used La 0.7 Ce 0.2 Tb 0.1 PO 4 bulk powder.

Hydrothermal synthesis and photoluminescence of Ce3+ and Tb3+ doped La2Sn2O7 nanocrystals

“…Pyrochlore-type lanthanum stannates have attracted enormous interest recently due to their excellent chemical and thermal stability, and ability to host rare earth ions in their crystal lattice, especially in the octahedrally coordinated site. Lanthanum compounds have been widely used as host materials for rare earth doped solid state lasers and phosphors [7][8][9]. It is expected that pyrochlore-type lanthanum stannate will be a promising host material for phosphors.…”

LaPO4:Eu3+, LaPO4:Ce3+, and LaPO4:Ce3+,Tb3+ nanocrystals: Oleic acid assisted solvothermal synthesis, characterization, and luminescent properties

“…To date, lanthanum orthophosphates (LaPO 4 ) doped with different RE ions have been reported to be prepared through various methods, including solidstate reaction [31], microwave approach [32,33], sol-gel process [34][35][36], wet-chemical precipitation [37], hydrothermal method [38,39]. However, the practical applicability of these phosphates as phosphors is still limited by their light output, quantum yield and emission, which are directly influenced by their synthesis process to restrict their size, morphology, purity and stoichiometry.…”

Construction of Highly Transparent Plasma Display Devices Using Hydrothermally Synthesized Green-Emitting LaPO4:Ce,Tb Nanophosphors

“…2a and the peak positions are well consistent with those of low-temperature hexagonal LaPO 4 phase (JCPDS 75-1881). Nanocrystalline LaPO 4 phase produced by a general hydrothermal method usually tends to grow anisotropically into a rod-shape, 14,18,26 even though the addition of co-solvent (e.g., ethylene glycol) 19 or the pH variation of mother mixture 28 can cause sphere-like morphologies. 2b.…”

“…[12][13][14][15][16][17][18][19][20][21][22] Among them, lanthanide orthophosphate (LnPO 4 , Ln ¼ La, Y, Gd) has been one of the most studied hosts for nano-sizing. [12][13][14][15][16][17][18][19][20][21][22] Among them, lanthanide orthophosphate (LnPO 4 , Ln ¼ La, Y, Gd) has been one of the most studied hosts for nano-sizing.…”

“…Green-emitting Ce 3þ -and Tb 3þ -codoped LaPO 4 (LaPO 4 :Ce,Tb) nanophosphor is in particular attractive because its bulk form exhibits excellent thermal, chemical stabilities at high temperature as well as a high quantum yield of > 70%. 18 Recently, we reported the synthesis of a modified citric acidassisted sol-gel-derived LaPO 4 :Ce,Tb nanophosphors, the formation of transparent nanophosphor layer, and their application to transparent PDD fabrication. 19 Although the latter methods usually result in an aggregated or semi-aggregated form of nanophosphors, they can provide practical synthetic merits such as low reaction temperature, high degree of homogeneity, simple processing, and facile production scale-up.…”