scholarly journals Rare Earth Doped Alkali Earth Sulfide Phosphors for White-Light LEDs

2011 ◽  
Vol 2011 ◽  
pp. 1-3 ◽  
Author(s):  
K. Suresh ◽  
K. V. R. Murthy ◽  
Ch. Atchyutha Rao ◽  
N. V. Poornachandra Rao
Keyword(s):  
Rare Earth ◽  
White Light ◽  
Light Emitting Diode ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
Light Emitting ◽  
Blue Led ◽  
Broadband Absorption ◽  
Application Requirements ◽  
Rare Earth Doped

CaS:Eu and SrS:Eu phosphors were synthesized by solid-state reaction. The effects of doping concentrations on luminescent properties of phosphors are investigated. The samples are excited using electroluminescent blue light emitting diode (460 nm) to examine them as potential coating phosphors for white-light LEDs. The excitation and emission spectra of these phosphors are broadband which can be viewed as the typical emission of Eu2+ ascribed to the 4f–5d transitions. Because of their broadband absorption in the region 400–630 nm, these phosphors meet the application requirements for blue LED chips. A white-light LED was fabricated through the integration of a 460 nm chip. The results indicate that these phosphors can be considered as candidates for the application in blue LED chip-based white-light LEDs.

Synthesis and Photoluminescence Properties of Two-Bands Excited SrSi2O2N2: Yb2+ Phosphors

2012 ◽  
Vol 430-432 ◽  
pp. 315-318 ◽  
Author(s):  
Xue Wen Xu ◽  
Kun Fu ◽  
Long Hu ◽  
Zun Ming Lu ◽  
Xing Hua Zhang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Blue Light ◽  
White Light ◽  
Light Emitting Diode ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
Chemical Compositions ◽  
Photoluminescence Properties ◽  
Light Emitting ◽  
Red Luminescence

The crystal structure and luminescent properties of synthesized SrSi2O2N2: Yb2+ phosphors have been investigated to seek for convention phosphor for white light-emitting diode applications. The Sr1-xYbxSi2O2N2 phosphors have yellow-red luminescence under the exciting of blue light, which is attributed to the 4fn↔4fn-15d transitions of Yb2+. Although the chemical compositions for Sr1-xYbxSi2O2N2 materials are different, no shifts are observed from the excitation and emission spectra.

Enhanced luminescence of Mn4+:Y3Al5O12red phosphor via impurity doping

2016 ◽  
Vol 4 (8) ◽  
pp. 1704-1712 ◽  
Author(s):  
Daqin Chen ◽  
Yang Zhou ◽  
Wei Xu ◽  
Jiasong Zhong ◽  
Zhenguo Ji ◽  
...  
Keyword(s):  
Rare Earth ◽  
White Light ◽  
Light Emitting Diodes ◽  
Glass Ceramics ◽  
Red Phosphor ◽  
Light Emitting ◽  
Impurity Doping ◽  
Enhanced Luminescence ◽  
White Light Emitting Diodes ◽  
Rare Earth Doped

A non-rare-earth doped Mn4+:Y3Al5O12red phosphor and the related glass–ceramics were fabricated to explore their application in white light-emitting diodes.

scholarly journals New emerging rare-earth free yellow emitting 2D BCNO nanophosphor for white light emitting diodes

2015 ◽  
Vol 39 (7) ◽  
pp. 5161-5170 ◽  
Author(s):  
Jaya Dwivedi ◽  
Pawan Kumar ◽  
Garima Kedawat ◽  
Bipin Kumar Gupta
Keyword(s):  
Rare Earth ◽  
White Light ◽  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Highly Efficient ◽  
White Light Emitting Diodes

Demonstration of a highly-efficient and lightweight yellow emitting 2D BCNO nanophosphor for CoB based white light emitting diode application.

scholarly journals High Efficiency and Color Rendering Quantum Dots White Light Emitting Diodes Optimized by Luminescent Microspheres Incorporating

Nanophotonics ◽  
2016 ◽  
Vol 5 (4) ◽  
pp. 565-572 ◽  
Author(s):  
Wei Chen ◽  
Kai Wang ◽  
Junjie Hao ◽  
Dan Wu ◽  
Jing Qin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
White Light ◽  
High Efficiency ◽  
Lattice Structure ◽  
Light Emitting Diode ◽  
Luminescent Properties ◽  
Color Temperature ◽  
High Quantum Efficiency ◽  
Light Emitting ◽  
Color Rendering

AbstractIn this research, we have developed an approach by incorporating quantum dots (QDs) with red emission into mesoporous silica microspheres through a non-chemical process and obtained luminescent microspheres (LMS). Owing to the lattice structure of LMS, QDs were effectively protected from intrinsic aggregation in matrix and surface deterioration by encapsulant, oxygen and moisture. The LMS composite has therefore maintained large extent luminescent properties of QDs, espe-cially for the high quantum efficiency. Moreover, the fabricated white light emitting diode (WLED) utilizing LMS and YAG:Ce yellow phosphor has demonstrated excellent light performance with color coordinates around (x = 0.33, y = 0.33), correlated color temperature between 5100 and 5500 K and color rendering index of Ra = 90, R9 = 95. The luminous efficiency of the WLED has reached up to a new record of 142.5 lm/W at 20 mA. LMS provide a promising way to practically apply QDs in lightings and displays with high efficiency as well as high stability.

Color Tunability of Blue Phosphors by Changing Cations for Near-UV InGaN-Based Light-Emitting Diode

2014 ◽  
Vol 986-987 ◽  
pp. 156-159
Author(s):  
Yi Wen Zhu ◽  
Fen Fen Hu ◽  
Mei Li Zhou ◽  
Ping Chen ◽  
Zheng Liang Wang
Keyword(s):  
Uv Light ◽  
Light Emitting Diode ◽  
Blue Emission ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
Blue Shift ◽  
Ionic Radii ◽  
Light Emitting ◽  
Triclinic Structure ◽  
The Difference

The serials of blue phosphors, CaAl2Si2O8: Eu2+ doped with different content Sr2+ and Mg2+ ions, were prepared by solid-state reaction at high temperature. And their structure and photo-luminescent properties were investigated. In Ca0.96-ySryAl2Si2O8: 0.04Eu2+ (y = 0.10, 0.30, 0.50, 0.70, 0.90) system, for y ≦ 0.03, all the compositions crystallize in triclinic structure of CaAl2Si2O8, and on further increase of y, the system undergoes a compositionally induced phase transition from triclinic to monoclinic structure. For Ca0.96-yMgyAl2Si2O8: 0.04Eu2+ (y = 0.10, 0.30, 0.50, 0.70, 0.90) system, for z ≦ 0.03, all the compositions are of triclinic structure of CaAl2Si2O8. With the further increase of z, other phase appears. The emission spectra of these phosphors show blue shift with the introduction of Sr2+ ions, and red shift with Mg2+ ions. The reason may be due to the difference ionic radii of Mg2+, Ca2+, Sr2+. These phosphors show excellent blue emission and broad excitation band in near-UV (ultraviolet) range. They may be potential phosphors for near-UV light-emitting diodes (LEDs).

The self-reduction synthesis and luminescent properties of Eu2+-Eu3+ activated BaZr0.2Si2O5.4 phosphors with white light emission for white light-emitting diodes

2018 ◽  
Vol 32 (04) ◽  
pp. 1850047 ◽  
Author(s):  
Jianlin Zhong ◽  
Lixin Yu ◽  
Songchu Li ◽  
Xiaoqin Man ◽  
Wei Sun
Keyword(s):  
White Light ◽  
Light Emission ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
White Light Emission ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
Broadband Emission ◽  
White Light Emitting Diodes

The BaZr[Formula: see text]Si2O[Formula: see text]: Eu[Formula: see text]/Eu[Formula: see text] phosphors were prepared with different concentrations of Eu2O3 by a self-reduction method under air condition. The X-ray diffraction and the photoluminescence properties of the prepared samples were analyzed. The emission spectra consisting of a broadband emission from the 4f[Formula: see text]5d transitions of Eu[Formula: see text] and sharp emissions from 5D0-7F[Formula: see text] (J = 0, 1, 2, 3, 4) transitions of Eu[Formula: see text] are observed. The different luminescent colors can be obtained and modulated by doping different concentrations of Eu2O3 and the white light emission can be observed as the concentration of europium is 6%.

The synthesis and luminescent properties of bonded Eu(III) polymer phosphors for white light‐emitting diode

2019 ◽  
Vol 57 (2) ◽  
pp. 627-634
Author(s):  
Jiandong Guo ◽  
Yamin Yang ◽  
Husheng Jia ◽  
Aiqin Zhang ◽  
Qianqian Shen ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diode ◽  
Luminescent Properties ◽  
Light Emitting
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