Laser action in pentaphosphate crystals

Journal of the American Ceramic Society

2011

The new red-emitting phosphors of Eu 31 -doped borotungstate Gd 4 B 2 WO 12 were prepared by the high-temperature solid-state reaction. The phosphors were characterized by X-ray powder diffraction technique. The photoluminescence excitation and emission spectra, the fluorescence decay curves and the dependence of luminescence intensity on temperature were investigated. The phosphor can be efficiently excited by near UV light to realize an intense red luminescence (618 nm) corresponding to the electric dipole transition 5 D 0 -7 F 2 of Eu 31 ions. The crystallographic site-occupations of the Eu 31 ions in Eu 4 B 2 WO 12 were investigated by the site-selective excitation and emission spectra, and the fluorescence decay curves in the 5 D 0 -7 F 0 region using a pulsed, tunable, and narrowband dye laser. The concentration quenching of the red luminescence together with the thermal stability were discussed on the base of the Eu 31 site-distributions in Eu 4 B 2 WO 12 host.

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

The Luminescence Properties of Eu³⁺‐Doped Borotungstate Gd₄B₂WO₁₂ Phosphors

Zhu

Journal of the American Ceramic Society

2011

“…However, in a Eu 3+ ‐concentrated compound EuBaB 9 O 16 , no concentration quenching could be detected. It has been found that some Eu 3+ compounds also show no concentration quenching at all, for example, EuP 5 O 14 24, K 5 Eu(MoO 4 ) 4 25. This kind of red phosphor is also favorable to suffer from high photon flux during its application without much luminescence quenching.…”

Section: Resultsmentioning

confidence: 99%

The red luminescence characteristics of fully concentrated Eu‐based phosphor EuBaB₉O₁₆

Hao

Physica Status Solidi (a)

2010

The red phosphor EuBaB 9 O 16 was prepared by the conventional solid-state reaction method. The crystallite phase of the phosphor was observed by X-ray diffraction (XRD) patterns. Scanning electron micrographs were obtained to study the morphologic features and the particle size of the phosphor. The photoluminescence (PL) excitation and emission spectra, temperature dependence of luminescence intensity and the decay curves were investigated. The phosphor, when excited with near-UV wavelength radiation, exhibited an intense red luminescence. The characteristic emission of Eu 3þ ions corresponding to the electric dipole transition 5 D 0 ! 7 F 2 was located at 613 nm under 254-and 365-nm excitation. Its room temperature fluorescent decay profile exhibits a singleexponent shape with a decay time of 2.03 ms. The color coordinates were also discussed. In addition, the PL properties of EuBaB 9 O 16 were compared with those of La 0.9 Eu 0.1 BaB 9 O 16 and Gd 0.9 Eu 0.1 BaB 9 O 16 .

“…In Eu 3+ -concentrated Eu 3 BWO 9 , no concentration quenching can be detected even if the Eu 3+ has a 100% concentration in the lattices, for example, the luminescence enhancement of Eu 3 BWO 9 could not be observed by substituting Eu 3+ with some Y 3+ or La 3+ ions. It has been found that some Eu 3+ compounds show no concen-tration quenching at all, 31 such as Eu 2 WO 6 , 32 EuP 5 O 14 , 33 EuBaB 9 O 16 , 34 etc. This red phosphor is very favorable to suffer from high photon flux during it application without many luminescence quenching.…”

Section: H1118mentioning

confidence: 99%

A Red-Emitting Phosphor of Eu-Based Borotungstate Eu[sub 3]BWO[sub 9] for White Light-Emitting Diodes

Zhu

2010

J. Electrochem. Soc.

The red-emitting phosphor normalEu3BWnormalO9 was prepared by the Pechini method. The phosphor was characterized by X-ray powder diffraction, scanning electron microscope, and photoluminescence measurements. It can be efficiently excited by near-ultraviolet and blue light and exhibits the far stronger red luminescence than the commercial normalY2normalO2S:normalEu3+ . The dependences of luminescence intensities and the color coordinates on the heating temperatures were investigated. The crystallographic site-occupations of Eu3+ ions in normalEu3BWnormalO9 were investigated by the site-selective excitation spectra in the normalD05→normalF07 region. The strong red luminescence together with its thermal stability were discussed on the base of the Eu3+ site distributions in normalEu3BWnormalO9 host. The phosphor would be a promising red component for solid-state lighting devices based on InGaN or GaN light-emitting diodes.