Preparation and photoluminescence study of Alumin o-boro silicate YAG fluorescent glass for White LED

Abstract The YAG: Eu 3+ fluorescent glass for NUV(near ultraviolet) white LEDs was obtained firstly by synthesizing Y 3 Al 5 O 12 (YAG): Eu 3+ precursors through a simple co-precipitation method, and then mixing precursor with B 2 O 3 -Al 2 O 3 -SiO 2 -Na 2 O-BaO glass powder calcined at 1400°C for 2.5 hours. The as-prepared YAG glass-ceramic phosphor was investigated by DTA, XRD, SEM, and photoluminescence (PL). Influence of YAG: Eu 3+ precursor and Eu 3+ doping on excitation and emission spectra also have been studied. The results show that: the phosphor's emission peak located at 393nm is correspond to the 7 F 0 - 5 L 6 transition of Eu 3+ ions, which matches good with UV LED chips; the phosphor gives intense emission at 593nm originating from the 5 D 0 - 7 F 1 transition of Eu 3+ ions. When the YAG precursor is 0.9g and amount of Eu 3+ doped is 0.08, the fluorescence excitation spectra of glass and emission spectra of the peak intensity reach its maximum value. The YAG: Eu 3+ fluorescence glass could be a promising material for the production of near ultraviolet chip white light-emitting diode.

Download Full-text

Synthesis and Luminescence Properties of Red Emitting Phosphors Na3CaB5O10:Eu3+

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.295-297.547 ◽

2011 ◽

Vol 295-297 ◽

pp. 547-550

Author(s):

Jia Yue Sun ◽

Jin Li Lai ◽

Hai Yan Du

Keyword(s):

Uv Light ◽

Emission Spectra ◽

Luminescent Properties ◽

Solid State Reaction Method ◽

Excitation Spectra ◽

Promising Candidate ◽

Light Emitting ◽

White Leds ◽

Near Ultraviolet ◽

Chromaticity Coordinates

A series of new Na3CaB5O10:Eu3+ phosphor was synthesized by a solid-state reaction method, and its luminescent properties were investigated. The phase formation of phosphors was confirmed by X-ray powder diffraction (XRD). The excitation spectra exhibited that the phosphors could be effectively excited by near ultraviolet (392 nm) and blue (464 nm) light, which perfectly match the emission wavelength of near-UV light-emitting diodes (LEDs). The emission spectra showed that two characteristic red emission lines peaking at 592 and 613 nm can be obtained upon 394 and 463 excitation with the chromaticity coordinates of (0.6347, 0.3649), which are due to 5D0- 7F1 and 5D0-7F2transitions of Eu3+ ions. The effect of Eu3+ concentration on the emission spectrum of Na3CaB5O10:Eu3+ phosphor was studied. The results showed that the emission intensity increased with increasing Eu3+ concentration, and then decreased because of concentration quenching. The obtained results indicated that this phosphor could be a promising candidate for near-UV white LEDs.

Download Full-text

Synthesis and luminescence properties of red-emitting K2MgSiO4:Eu3+ phosphors

International Journal of Modern Physics B ◽

10.1142/s0217979217440581 ◽

2017 ◽

Vol 31 (16-19) ◽

pp. 1744058

Author(s):

Rong Yang ◽

Huidong Tang

Keyword(s):

Decay Curve ◽

Emission Spectra ◽

Solid State Reaction Method ◽

Excitation Spectra ◽

Red Phosphor ◽

Light Emitting ◽

X Ray ◽

Dipole Interactions ◽

Near Ultraviolet ◽

White Light Emitting Diodes

A novel phosphor, K2MgSiO4:Eu[Formula: see text], was synthesized by a solid-state reaction method. The phase formation was checked by X-ray powder diffraction. The photoluminescence excitation, emission spectra, decay curve and CIE coordinates of samples with different Eu[Formula: see text] ion concentrations were investigated in detail. The excitation spectra show a broad wavelength range of 225–470 nm. The K2MgSiO4:Eu[Formula: see text] phosphors exhibit highly red emission peaking at about 616 nm which is assigned to the 5D[Formula: see text]F2 transition of Eu[Formula: see text]ions under the excitation of near-ultraviolet (NUV) (394 nm) light. The critical quenching concentration of Eu[Formula: see text] doped in the K2MgSiO4: Eu[Formula: see text] phosphors was about 10 mol.% and the concentration quenching mechanism was dipole–dipole interactions between Eu[Formula: see text] ions. The results indicate that K2MgSiO4:Eu[Formula: see text] is a potential red phosphor candidate for NUV-pumped white light emitting diodes.

Download Full-text

Synthesis and luminescence properties of (Lu0.95−xCe0.05)2Ca1+2xMg2Si3O12 silicate garnet phosphors and its applications

Functional Materials Letters ◽

10.1142/s1793604716500491 ◽

2016 ◽

Vol 09 (03) ◽

pp. 1650049

Author(s):

Wei Xia ◽

Xiyan Zhang ◽

Liping Lu

Keyword(s):

Light Emitting Diode ◽

Red Light ◽

Emission Spectra ◽

Peak Wavelength ◽

Excitation Peak ◽

Light Emitting ◽

White Leds ◽

Reducing Atmosphere ◽

Color Rendering ◽

Silicate Garnet

Silicate garnet phosphors (Lu[Formula: see text]Ce[Formula: see text]Ca[Formula: see text]Mg2Si3O[Formula: see text] with [Formula: see text], 0.05, 0.1, and 0.15 were prepared by high-temperature solid-state reaction in a reducing atmosphere. The crystal structure, photoluminescence and luminescence of the phosphors were investigated. The optimum excitation peak wavelength of the phosphors ranged from 450[Formula: see text]nm to 490[Formula: see text]nm, matching the emission spectra of a blue light-emitting diode chip. The phosphors emit orange-red light after excitation that can be tuned from 589[Formula: see text]nm to 597[Formula: see text]nm by changing the concentration of calcium ions. In addition, their emission made them suitable for use in warm-white LEDs with a high-color rendering index.

Download Full-text

Development of a Novel Fluorimeter Based on Superluminescent Light-Emitting Diodes and Acousto-Optic Tunable Filter and its Application in the Determination of Chlorophylls a and b

Applied Spectroscopy ◽

10.1366/0003702971939578 ◽

1997 ◽

Vol 51 (11) ◽

pp. 1603-1606 ◽

Cited By ~ 5

Author(s):

Troy A. Alexander ◽

Guan-Hong Gao ◽

Chieu D. Tran

Keyword(s):

Light Emitting Diodes ◽

Light Emitting Diode ◽

Emission Spectra ◽

High Sensitivity ◽

Tunable Filter ◽

Excitation Spectra ◽

Excitation Light ◽

Light Emitting ◽

Chlorophylls A And B

A novel, compact, inexpensive fluorimeter that has high sensitivity and no moving parts has been developed by using super luminescent (bright-blue) light-emitting diodes (SLEDs) and an acousto-optic tunable filter (AOTF). In this instrument, the recently developed gallium nitride SLEDs were used in a counterpropagating configuration to provide excitation light. These SLEDs provide not only high intensity (several milliwatts) but also wide spectral bandwidth in the blue region (from 370 to 570 nm). The AOTF can be placed before the sample to facilitate the measurements of excitation spectra or after the sample for the emission spectra measurements. This fluorimeter is suitable for the sensitive and general fluorescent analysis of a variety of compounds. It has been used, as an example, for the sensitive and simultaneous determination of chlorophylls a and b. Detection limits of 2.30 × 10−9 and 1.10 × 10−9 M have been achieved for chlorophyll a and chlorophyll b, respectively. Index Headings: Superluminescent light-emitting diode; Acousto-optic tunable filter; Fluorescence; Chlorophyll.

Download Full-text

A broadband cyan-emitting Ca2LuZr2(AlO4)3:Ce3+ garnet phosphor for near-ultraviolet-pumped warm-white light-emitting diodes with an improved color rendering index

Journal of Materials Chemistry C ◽

10.1039/c9tc04952e ◽

2020 ◽

Vol 8 (3) ◽

pp. 1095-1103 ◽

Cited By ~ 31

Author(s):

Liangling Sun ◽

Balaji Devakumar ◽

Jia Liang ◽

Shaoying Wang ◽

Qi Sun ◽

...

Keyword(s):

White Light ◽

Light Emitting Diodes ◽

Emission Spectra ◽

Light Emitting ◽

White Leds ◽

Near Ultraviolet ◽

Warm White Light ◽

Color Rendering Index ◽

White Light Emitting Diodes ◽

Color Rendering

Broadband cyan-emitting Ca2LuZr2(AlO4)3:Ce3+ garnet phosphors enabled to fill the cyan gap in the emission spectra of near-ultraviolet-pumped warm-white LEDs, thus resulting in improved color rendering index.

Download Full-text

The Structure and Photoluminescence Properties of Ca3Si2O7: Eu2+ Phosphor

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.509.192 ◽

2012 ◽

Vol 509 ◽

pp. 192-196

Author(s):

Xing Hua Zhang ◽

Zun Ming Lu ◽

Fan Bin Meng ◽

Long Hu ◽

Xue Wen Xu ◽

...

Keyword(s):

Light Emitting Diode ◽

Solid State Reaction Method ◽

Emission Region ◽

Photoluminescence Properties ◽

Phosphor Particle ◽

Sem Images ◽

Host Matrix ◽

Light Emitting ◽

White Leds ◽

Near Ultraviolet

A series of yellow-emitting phosphors based on a silicate host matrix, Ca3-xSi2O7: xEu2+, were prepared by solid-state reaction method. The structure and photoluminescent properties of the phosphors were investigated. The XRD results show that the Eu2+ substitution of Ca2+ does not change the structure of Ca3Si2O7 host. The SEM images display that phosphors aggregate obviously and the shape of the phosphor particle is irregular. The EDX results reveal that the phosphors consist of Ca, Si, O, and Eu elements. The Ca3-xSi2O7: xEu2+ phosphors can be excited at wavelength of 300-490 nm, which is suitable for the emission band of near ultraviolet or blue light-emitting-diode (LED) chips. The phosphors exhibit a broad emission region from 520 to 650 nm and the emission peak centered at 568 nm. The phosphor for has the strongest excitation and emission intensity, and the energy transfer style between Eu2+ ions is quadrupole-quadrupole interaction for higher concentration Eu2+ doped Ca3Si2O7 phosphor. The Ca3-xSi2O7: xEu2+ phosphors can be used as candidates for white LEDs.

Download Full-text