scholarly journals Lu3+ doping induced photoluminescence enhancement in novel high-efficiency Ba3Eu(BO3)3 red phosphors for near-UV-excited warm-white LEDs

RSC Advances ◽  
2018 ◽  
Vol 8 (59) ◽  
pp. 33710-33716 ◽  
Author(s):  
Bin Li ◽  
G. Annadurai ◽  
Jia Liang ◽  
Liangling Sun ◽  
Shaoying Wang ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
High Efficiency ◽  
Internal Quantum Efficiency ◽  
White Leds ◽  
Red Phosphors ◽  
Photoluminescence Enhancement

Novel high-efficiency Ba3Eu(BO3)3:Lu3+ red phosphors with internal quantum efficiency as great as 87% were developed for near-UV-excited warm-white LEDs.

Synthesis and Photoluminescence Properties of Sc0.88-xLu0.05VO4:Eu3+0.07,Bi3+x Red Phosphor

2017 ◽  
Vol 727 ◽  
pp. 604-611
Author(s):  
Di Wu ◽  
Xin Yu Ye ◽  
Xin Hua Yang ◽  
Jian Zhou ◽  
Xiao Qiang Wen ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
Emission Intensity ◽  
Doping Concentration ◽  
Internal Quantum Efficiency ◽  
The Body ◽  
Luminescence Spectra ◽  
Intensity Increase ◽  
X Ray Diffraction ◽  
Red Phosphor ◽  
Red Phosphors

Sc0.88-xLu0.05VO4:Eu3+0.07,Bi3+x(0≤x≤0.05) red phosphors were synthesized by solid state reaction at 1200°C for 3h. The structure, morphology and luminescence spectra of samples are investigated by X-ray diffraction (XRD), Scanning electron microscope (SEM) and fluorescence spectrophotometer, respectively. The samples doped with Eu3+, Lu3+ and Bi3+ maintain the body-centered tetragonal structure of ScVO4 and the morphology remains essentially unchanged with slight agglomeration. The excitation spectrum of Sc0.88-xLu0.05VO4:Eu3+0.07,Bi3+x emerged redshift and the excitation intensity increase within the near UV excitation (360-400nm). The optimum doping concentration of Bi3+ is 0.02(x value), and the maximum emission intensity of Sc0.86Lu0.05VO4:Eu3+0.07,Bi3+0.02 is higher than 88 % in comparison with Sc0.88Lu0.05VO4:Eu3+0.07 under 365 nm excitation. Decay curve of 5D0 state for as-prepared samples fits the single order exponential behavior, the lifetime of 5D0 increase first and then decrease with the increase of Bi3+ doping concentration. The internal quantum efficiency is up to 74.08% under 365nm excitation; When the temperature raises to 200°C, the emission intensity maintains 79% of that in the room temperature. Sc0.86Lu0.05VO4:Eu3+0.07,Bi3+0.02 phosphor show high internal quantum efficiency and thermal stability, which is suitable for the UV-pumped white LED as red phosphor.

Enhanced Luminescence Efficiency for Bi, Eu Doped Y2O3 Red Phosphors for White LEDs

2007 ◽  
Vol 124-126 ◽  
pp. 379-382 ◽  
Author(s):  
W.J. Park ◽  
M.K. Jung ◽  
Dae Ho Yoon
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
High Efficiency ◽  
Broad Band ◽  
Weak Band ◽  
White Leds ◽  
Red Phosphors ◽  
Luminescence Efficiency ◽  
Precipitation Synthesis ◽  
Co Precipitation

Bi and Eu co-doped Y2O3 was used as a red phosphor with a very high efficiency synthesized by the solid state reaction and co-precipitation The emission spectrum consisted of a weak band at 581, 587, 593 and 599 nm corresponding to the 5D0 → 7F1 transition, with sharp peaks of maximum intensity occurring at about 611 nm due to the 5D0 → 7F2 transition of Eu3+. In addition, the excitation spectrum exhibited a broad band between 250 and 550 nm with peaks occurring at about 310 – 400 nm and a sharp peak at 465.5 nm. The relative emission intensity was improved by co-precipitation synthesis as compared to solid state reaction synthesis. This implies that an appropriate co-precipitation synthesis could improve the luminescent efficiency, particularly for the samples prepared with the optimized firing temperature of 1100 °C.

Considerable photoluminescence enhancement of LiEu(MoO4)2 red phosphors via Bi and/or Si doping for white LEDs

2015 ◽  
Vol 625 ◽  
pp. 355-361 ◽  
Author(s):  
Qing-Feng Wang ◽  
Ying Liu ◽  
Yu Wang ◽  
Wenxi Wang ◽  
Yi Wan ◽  
...  
Keyword(s):  
White Leds ◽  
Red Phosphors ◽  
Si Doping ◽  
Photoluminescence Enhancement

Highly efficient near-UV-excitable Ca2YHf2Al3O12:Ce3+,Tb3+ green-emitting garnet phosphors with potential application in high color rendering warm-white LEDs

2020 ◽  
Vol 8 (13) ◽  
pp. 4408-4420 ◽  
Author(s):  
Shaoying Wang ◽  
Balaji Devakumar ◽  
Qi Sun ◽  
Jia Liang ◽  
Liangling Sun ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Potential Application ◽  
Internal Quantum Efficiency ◽  
White Leds ◽  
Highly Efficient ◽  
Color Rendering

Novel near-UV-excitable Ca2YHf2Al3O12:Ce3+,Tb3+ green phosphors with a highest internal quantum efficiency of 86.6% and external quantum efficiency of 63.1% were reported for high-CRI warm-white LEDs.

Synthesis and photoluminescence enhancement of Ca3Sr3(VO4)4:Eu3+ red phosphors by Sm3+ doping for white LEDs

2017 ◽  
Vol 28 (24) ◽  
pp. 18686-18696 ◽  
Author(s):  
Qinxue Tang ◽  
Kehui Qiu ◽  
Junfeng Li ◽  
Wentao Zhang ◽  
Yu Zeng
Keyword(s):  
White Leds ◽  
Red Phosphors ◽  
Photoluminescence Enhancement

The Optical Properties of Dual-Wavelength InxGa1−xN/GaN Nanorods for Wide-Spectrum Light-Emitting Diodes

2020 ◽  
Vol 142 (3) ◽  
Author(s):  
Jie Zhao ◽  
Xuecheng Wei ◽  
Dongdong Liang ◽  
Qiang Hu ◽  
Jianchang Yan ◽  
...  
Keyword(s):  
Stark Effect ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Internal Quantum Efficiency ◽  
Wide Spectrum ◽  
Dual Wavelength ◽  
Planar Structure ◽  
Nonradiative Recombination ◽  
Light Emitting ◽  
White Leds

Abstract We fabricated the dual-wavelength InxGa1−xN/GaN nanorods for wide-spectrum light-emitting diodes (LEDs) by silica nanosphere lithography (SNL) technique. The emission properties of the dual-wavelength nanorods are characterized by micro-photoluminescence (micro-PL), cathodoluminescence (CL), and temperature-dependent PL (TDPL) measurements. Nanorod structure can effectively suppress quantum confined Stark effect (QCSE) compared with planar structure due to the strain relaxation. In addition, the internal quantum efficiency (IQE) of the green quantum well (QW) within nanorod structure increases, but the IQE of the blue QW clearly decreases because blue QW has severely suffered from the nonradiative recombination by surface damage. Furthermore, the IQEs of the green QW and the blue QW within the nanorod structure can be effectively improved by wet etching treatment, with an increase in factor by 1.3 when compared with unetched nanorod structure. Evidently, the dual-wavelength InxGa1−xN/GaN nanorods are beneficial to improve the optical performance compared with planar structure, presenting a potential to realize monolithic, high-efficiency, and cost-effective white LEDs.

High-efficiency and thermal-stable Ca3La(GaO)3(BO3)4:Eu3+ red phosphors excited by near-UV light for white LEDs

2018 ◽  
Vol 157 ◽  
pp. 40-46 ◽  
Author(s):  
Jia Liang ◽  
Peng Du ◽  
Heng Guo ◽  
Liangling Sun ◽  
Bin Li ◽  
...  
Keyword(s):  
High Efficiency ◽  
Uv Light ◽  
White Leds ◽  
Red Phosphors ◽  
Thermal Stable
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