scholarly journals Effects of Bi3+ Ion-Doped on the Microstructure and Photoluminescence of La0.97Pr0.03VO4 Phosphor

2021 ◽  
Vol 6 (3) ◽  
pp. 191-198
Author(s):  
Hao-Long Chen ◽  
Hung-Rung Shih ◽  
Sean Wu ◽  
Yee-Shin Chang
Keyword(s):  
White Light ◽  
Emission Intensity ◽  
Sol Gel ◽  
Blue Shift ◽  
Light Emitting ◽  
Light Region ◽  
Chromaticity Coordinates ◽  
Ion Doping ◽  
Ion Contents ◽  
Cie Chromaticity

The objective of this paper is to enhance the emission intensity of La0.97Pr0.03VO4 single-phased white light emitting phosphor. The Bi3+ ion-doped La0.97Pr0.03VO4 single-phased white light emitting phosphors are synthesized using a sol-gel method. The structure and photoluminescence properties of (La0.97-yBiy)Pr0.03VO4 (y = 0-0.05) phosphor are also examined. The XRD results show that the structure of La0.97Pr0.03VO4 phosphors with different concentrations of Bi3+ ion doping keeps the monoclinic structure. The SEM results show that the phosphor particles become smoother when the Bi3+ ion is doped. The excitation band for La0.97Pr0.03VO4 phosphor exhibits a blue shift from 320 nm to 308 nm as the Bi3+ ion contents are increased. The maximum emission intensity is achieved for a Bi3+ ion content of 0.5 mol%, which is about 30% greater than that with no Bi3+ ion doped. The CIE chromaticity coordinates are all located in the near white light region for different Bi3+ ion-doped La0.97Pr0.03VO4 phosphors.

Perovskite white light-emitting diodes with a perovskite emissive layer blended with rhodamine 6G

2020 ◽  
Vol 8 (37) ◽  
pp. 12951-12958 ◽  
Author(s):  
Che-Yu Chang ◽  
Wei-Li Hong ◽  
Pei-Hsuan Lo ◽  
Tzu-Hsiang Wen ◽  
Sheng-Fu Horng ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Rhodamine 6G ◽  
Light Emitting ◽  
Emissive Layer ◽  
Chromaticity Coordinates ◽  
Halide Perovskites ◽  
Cie Chromaticity ◽  
White Light Emitting Diodes

Perovskite white light-emitting diodes with only a single emissive layer of halide perovskites and rhodamine 6G were realized with the CIE chromaticity coordinates of (0.33, 0.40).

High color rendering index single phase white light emitting phosphors based on Tb3+/Sm3+ co-doped CePO4 nanocrystals: the role of Tb3+ as a bridge between Ce3+ and Sm3+

2019 ◽  
Vol 43 (44) ◽  
pp. 17367-17382 ◽  
Author(s):  
Sisira S. ◽  
Linju Ann Jacob ◽  
Kamal P. Mani ◽  
Biju P. R. ◽  
N. V. Unnikrishnan ◽  
...  
Keyword(s):  
White Light ◽  
Single Phase ◽  
Color Temperature ◽  
Light Emitting ◽  
Chromaticity Coordinates ◽  
Color Rendering Index ◽  
Cie Chromaticity ◽  
Color Rendering

Single phase white light emitting CePO4 nanocrystals doped with Tb3+ and Sm3+ were synthesized. The quality of white light is characterized by CIE chromaticity coordinates, color temperature, color rendering index and quantum yield.

Perovskite white light-emitting diodes based on a molecular blend perovskite emissive layer

2019 ◽  
Vol 7 (28) ◽  
pp. 8634-8642 ◽  
Author(s):  
Che-Yu Chang ◽  
Alexander N. Solodukhin ◽  
Shih-Yu Liao ◽  
K. P. O. Mahesh ◽  
Ching-Ling Hsu ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Emissive Layer ◽  
Chromaticity Coordinates ◽  
Cie Chromaticity ◽  
White Light Emitting Diodes

Perovskite white light-emitting diodes with only a single emissive layer were realized with CIE chromaticity coordinates of (0.3, 0.49).

Improved Efficiency in Organic Light Emitting Device with a Excton Confining Structure

2013 ◽  
Vol 750-752 ◽  
pp. 1063-1067
Author(s):  
Hui Shan Yang ◽  
Li Shuang Wu ◽  
Yu Zhuo Pan
Keyword(s):  
Current Efficiency ◽  
White Light ◽  
Light Emission ◽  
Operating Voltage ◽  
Maximum Luminance ◽  
Light Emitting ◽  
Organic Light ◽  
Chromaticity Coordinates ◽  
Cie Chromaticity ◽  
Two Peaks

A white organic light emitting device (WOLED) with excton confining structure is reported. The blue and red emitting layer consist of 1,4bis (2,2-diphenyl vinyl) benzene (DPVBi) and the bis (1-(phenyl) isoquinoline) iridium (III) acetylanetonate [Ir (piq)2(acac)] doped into 4,4(-N,N)-dicarbazole-biphenyl (CBP) host, respectively. The devices were made of ITO/ m-MTDATA (40 nm)/ NPB (10 nm) /DPVBi (8 nm)/ Bhen (xnm)/ CBP: Ir (piq)2(acac) 2% 5nm/ Alq (50 nm )/ LiF (1 nm)/Al (200 nm), by adding excton confining layer, with only a small increase in operating voltage. However, the efficiency of device increases. The electroluminescent (EL) spectra exhibit two peaks at 456 and 628 nm, resulting in white light emission with the Commission Internationale dEclairage (CIE) chromaticity coordinates of (0.222, 0.2402) at 4V to (0.1924, 0.1986) at 13V whenxis 8, while the device shows the current efficiency of 4.79 cd/A at 6V, its maximum luminance is 14130 cd/m2at 13V, respectively.

White Light Emission from Pr, Dy Doped ZnSiCa Glass

2020 ◽  
Vol 12 (2) ◽  
pp. 154-160
Author(s):  
Pingsheng Yu ◽  
Wei Guo ◽  
Yilu Cheng ◽  
Liangbi Su ◽  
Jun Xu
Keyword(s):  
White Light ◽  
Light Emission ◽  
Light Emitting Diode ◽  
Visible Region ◽  
Color Temperature ◽  
Potential Candidate ◽  
Rare Earth Ion ◽  
Light Emitting ◽  
Light Region ◽  
Chromaticity Coordinates

Background:: Luminescence glass is a potential candidate for developing white light emitting diode (W-LED) due to its good rare earth ion solubility, efficient luminescence, easy fabrication and good mold ability. Pr3+ ion has various visible emission bands from blue to red spectral region, and has attracted considerable attention for potential application to LEDs, ultraviolet laser, and scintillator. The Dy3+ ions can exhibit emission in blue and greenish-yellow (4F9/2→6H15/2, 13/2 transitions of Dy3+) spectral regions under excitation at near UV (ultraviolet). It is possible to obtain white luminescence if Pr3+ ions and Dy3+ ions can be excited simultaneous, due to their multiple luminescence in the visible region. Methods: The Pr, Dy doped ZnSiCa glass samples were prepared by the conventional melting quenching procedure. The XRD, absorption spectra, emission spectra, and ICP-OES measurements were performed to investigate the properties of the materials. Results: The Pr and Dy co-doped ZnSiCa glasses under 443 nm excitation show emission band peaking at about 483 nm, 575 nm and 670 nm / 676 nm. The glass samples exhibit chromaticity coordinates in the white light region in the CIE 1931 diagram, with a Correlated Color Temperature (CCT) at about 7000 K. Conclusion: Pr, Dy codoped ZnSiCa glass samples show chromaticity coordinates in the white light region in the CIE 1931 diagram, with a CCT at about 7000 K. It is suggested that the Pr, Dy codoped ZnSiCa glasses might be considered as promising candidates for white light emitting sources.

scholarly journals Broad near-ultraviolet and blue excitation band induced dazzling red emissions in Eu3+-activated Gd2MoO6 phosphors for white light-emitting diodes

RSC Advances ◽  
2017 ◽  
Vol 7 (6) ◽  
pp. 3170-3178 ◽  
Author(s):  
Peng Du ◽  
Yue Guo ◽  
Soo Hyun Lee ◽  
Jae Su Yu
Keyword(s):  
Citric Acid ◽  
White Light ◽  
Light Emitting Diodes ◽  
Sol Gel ◽  
Excitation Band ◽  
Light Emitting ◽  
Near Ultraviolet ◽  
Blue Excitation ◽  
White Light Emitting Diodes

A series of Eu3+-activated Gd2MoO6 phosphors were synthesized via a citric acid-assisted sol–gel route.

The Morphologies and Photoluminescence of Ce3+-Doped 0.5La2O3-2SrO-0.5Al2O3 Phosphors with SrF2

2016 ◽  
Vol 680 ◽  
pp. 228-232
Author(s):  
Xi Guang Gu ◽  
Ren Li Fu ◽  
Ye Tang ◽  
Fang Yang
Keyword(s):  
Solid State ◽  
White Light ◽  
Solid State Reaction ◽  
Emission Intensity ◽  
Solid State Reaction Method ◽  
Conventional Solid State Reaction ◽  
Light Emitting ◽  
Reaction Method ◽  
Reducing Atmosphere ◽  
White Light Emitting Diodes

Ce3+-doped 0.5La2O3-2SrO-0.5Al2O3 (LSA:Ce) phosphors had been successfully synthesized using a conventional solid-state reaction method under reducing atmosphere (H2/N2 =1/5). The phase, morphologies and luminescence properties of the LSA:Ce phosphors were investigated. The emission intensity of LSA:Ce phosphors was improved by the addition of SrF2 as flux, and red shift of PL spectra peak was observed in this phosphors. Research results shown that the LSA:Ce phosphors have the potential to meet the development of white light-emitting diodes.

Photoluminescence studies on LiNa5(PO4)2:Dy3+, Sm3+ phosphor

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Miyapuram Ravi ◽  
Ghanta Pushpa Chakrapani ◽  
Mandava Balachandrika ◽  
Pavuluri Vasudevarao ◽  
Chendela Nageswararao ◽  
...  
Keyword(s):  
White Light ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
New Class ◽  
Light Region ◽  
Crystalline Nature ◽  
Photoluminescence Studies ◽  
White Light Emitting Diodes ◽  
Good Agreement ◽  
Pure White

Abstract This paper describes the preparation, structure and photoluminescence properties of a new class LiNa5(PO4)2:Dy3+, Sm3+-phosphor. Crystalline nature confirmed by X-ray diffraction. The phases obtained are in good agreement with the standard phase. Excitation dependence and concentration effect on luminescence features are investigated. Color purity and optical bandgap are also estimated for the LiNa5(PO4)2:Dy3+, Sm3+ phosphors. The result shows LiNa5(PO4)2:Dy3+, Sm3+-phosphor excited by 374 nm nUV light produces pure white light than others. Admixing of 4f configurations and energy transfer between dopants are identified while varying the concentration of Sm3+. The CIE coordinates for LiNa5(PO4)2:0.05Dy3+, 0.05Sm3+ (x = 0.309, y = 0.332) are positioned well in white light region and very close to pure white light. The present study on LiNa5(PO4)2:Dy3+, Sm3+-phosphor suggests that it is useful for the fabrication of white light emitting diodes.

scholarly journals Chromaticity Study of Curcumin Dye Extracted from Curcuma longa L. Using for UV Light down Conversion for White Light Emitting Diode

2019 ◽  
Vol 290 ◽  
pp. 183-189
Author(s):  
Mahmood Al Shafouri ◽  
Naser Mahmoud Ahmed ◽  
Zainuriah Hassan ◽  
Munirah Abdullah Almessiere
Keyword(s):  
White Light ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Curcuma Longa ◽  
Color Temperature ◽  
Light Emitting ◽  
Chromaticity Coordinates ◽  
Major Factors ◽  
Color Rendering ◽  
Down Conversion

In thus study, Turmeric phosphor dye was extracted from Curcuma Longa L. via a simple technique using silica gel. The phosphor was used for light down-conversion of UV light for the manufacture white light emitting diode (WLED). The UV-LED was analyzed over 395nm wavelengths. The characteristics of the white light chromaticity were controlled by tuning the current and phosphor concentration. An optimum color rendering index (CRI) value of 63.4 was obtained. The chromaticity coordinates (CIE) and correlated color temperature (CCT) were measured for various currents and phosphor concentrations. The white phosphor exhibited CIE value of 0.355,0.338 and CCT of 4567 K. The concentration of phosphor and amount of applied current were confirmed to be major factors that control the intensity of white light emitted from the sample, where CIE and CRI of the emitted light steadily increased with the concentration of phosphor and current. Thus, phosphor concentration has a critical effect on conversion efficiency. Key words: Turmeric, phosphor, WLED, curcumin

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