Highly efficient low-voltage cathodoluminescence of LaF3:Ln3+ (Ln=Eu3+,Ce3+,Tb3+) spherical particles

Abstract

Spherical particles of rare-earth doped LaF 3 are synthesized through refluxing in glycerol/water media. The low-voltage cathodoluminescence of LaF 3 : Eu due to 5 D 0 → 7 F 1 and 5 D 0 → 7 F 2 transitions was found to be sensitive to the site that Eu 3+ ions occupied. The luminous efficiency of LaF 3 :Ce 3+ , Tb 3+ with green emission is improved from 1.53 to 2.02 lm/W compared with LaF 3 :Tb 3+ , due to the energy transfer processes from Ce 3+ to Tb 3+ ions. Our results suggest that the obtained spherical particles of rare-earth doped LaF 3 are promising as highly efficient low-voltage cathodoluminescent phosphors, which have received considerably less attention.

Structure, composition, morphology, photoluminescence and cathodoluminescence properties of ZnGeN2 and ZnGeN2:Mn2+ for field emission displays

“…So far, most research on cathodoluminescence (CL) of rare-earth or transitional-metal ion has been carried on oxide and sulfide phosphors [4][5][6][7]. Unfortunately, these conventional cathode ray tube (CRT) phosphors do not meet these requirements for FED application, owing to their poor chemical stability, low emission efficiency and/or worse electrical conductivity [8,9]. Most recently, Hirosaki and co-workers developed a novel blue-emitting AlN:Eu 2+ nitride phosphor [10].…”

Rare earth based nanostructured materials: synthesis, functionalization, properties and bioimaging and biosensing applications

“…This quenching is proportional to the number of vibrational quanta of the matrix that are needed to bridge the gap between the lowest emitting level and the highest non-emitting level of the lanthanide ion and decreases rapidly as the number of vibrational quanta increases [191]. As previously mentioned, fluoride-based matrices normally possess low phonon energies (<400 cm −1 ) which leads to the low probability of NR decays, and consequently the luminescence quantum yields are usually higher than in oxide hosts and in most inorganic matrices [178,192]. For example, NaREF 4 (RE = Pr to Lu and Y, in particular the β polymorph) and CaF 2 matrices are commonly employed for UCNPs, due to their higher upconversion efficiencies [81,[193][194][195].…”

“…Regarding the matrices of Ln-based luminescent materials, a wide variety of inorganic structures for both DC and UC materials have been proposed in the literature. Fluorides are used for their low phonon energy (<400 cm −1 ), which involves a low probability of NR relaxation and therefore provides improved quantum efficiency [177,178], while phosphates are interesting for their biocompatibility and biodegradability [179]. Other matrices based on vanadates [86,180], oxyfluorides [92], wolframates [181][182][183] and molybdates [184,185] are employed to enhance the global luminescent emission of the DC materials, as it will be detailed later.…”

Synthesis and luminescence of sub-micron sized Ca3Sc2Si3O12:Ce green phosphors for white light-emitting diode and field-emission display applications

“…The gel-combustion method has lots of advantages such as a usage of inexpensive precursors, facile operation, low firing temperature, energy efficiency and small particles with narrow size distribution in the obtained product. In addition to the photoluminescence (PL), in our earlier reports the cathodoluminescence (CL) and electroluminescence (EL) properties of materials were found to be essential for fieldemission displays (FEDs) and EL displays, respectively, [10][11][12] which are promising emissive displays realizing high resolution and low consumption of electric power. Low-voltage CL properties of Ca 3 Sc 2 Si 3 O 12 :Ce 3+ have not been reported so far.…”