scholarly journals White-Light-Emitting Control via Lead-free Perovskite Material

2021 ◽  
Vol 2076 (1) ◽  
pp. 012044
Author(s):  
YueLin Xie ◽  
Tingxuan Chen ◽  
Henan Li ◽  
Shaofan Fang
Keyword(s):  
White Light ◽  
Lead Free ◽  
Molar Ratio ◽  
Strong Light ◽  
Characterization Methods ◽  
Light Emitting ◽  
Perovskite Material ◽  
Powder Samples ◽  
Low Dimensional ◽  
Cie Chromaticity

Abstract In recent years, the emerging lead-free halide perovskites are attracting great attention in the field of the optical detection and luminescence due to its inherent strong light absorption and high balanced carrier on transmission characteristics. This experiment attempts to explore the way of grinding to prepare the white light emitting materials that does not contain lead. Low dimensional lead-free copper-based halide luminescent materials are prepared by controlling the molar ratio of a series of lead-free perovskite materials Cs3Cu2I5 and CsCu2I5. As-synthesized powder samples are characterized by powder X-ray diffraction (XRD), photoluminescence spectrum (PL), photoluminescence excitation spectrum (PLE) and photoluminescence quantum yield (PLQY) and other characterization methods. We successfully prepare the white powder sample by controlling the molar ratio of reactants (CsI:CuI=1:3). We measure the Commission Internationale de l’Eclairage (CIE) chromaticity coordination of PL spectra for the samples which can be regulated by the ratio of reactants. Moreover, it is demonstrated that acetone can effectively promote the reaction of reactants. These findings make this material be a stable and environmentally friendly white luminescent material, which has the potential to be used in white LED applications.

Coordination Units of Mn2+ Modulation toward Tunable Emission in Zero-Dimensional Bromides for White Light-Emitting Diodes

2022 ◽  
Author(s):  
Guojun Zhou ◽  
Jialiang Ding ◽  
Xing-Xing Jiang ◽  
Jian Zhang ◽  
Maxim Molokeev ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Lead Free ◽  
Metal Halides ◽  
Light Emitting ◽  
High Efficient ◽  
White Light Emitting Diodes ◽  
Multifunctional Platform ◽  
Tunable Emission

Organic-inorganic metal halides have become a multifunctional platform for manipulating photoluminescence due to high-efficient and tunable emissions, especially for lead-free Mn2+-based halides. Herein, the zero-dimensional (0D) bromides of (C5H14N3)2MnBr4 and...

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.

Ultrastable Lead-Free Double Perovskite Warm-White Light-Emitting Devices with a Lifetime above 1000 Hours

2020 ◽  
Vol 12 (41) ◽  
pp. 46330-46339
Author(s):  
Sen Li ◽  
Zhifeng Shi ◽  
Fei Zhang ◽  
Lintao Wang ◽  
Zhuangzhuang Ma ◽  
...  
Keyword(s):  
White Light ◽  
Double Perovskite ◽  
Lead Free ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Warm White Light

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).

scholarly journals Preparation of Bismuth Oxide Photocatalyst and Its Application in White-light LEDs

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Yen-Chang Chu ◽  
Gang-Juan Lee ◽  
Chin-Yi Chen ◽  
Shih-Hsin Ma ◽  
Jerry J. Wu ◽  
...  
Keyword(s):  
Bismuth Oxide ◽  
White Light ◽  
Front Surface ◽  
Color Temperature ◽  
Spray Pyrolysis Method ◽  
Light Emitting ◽  
White Leds ◽  
Air Purifier ◽  
Cie Chromaticity ◽  
White Light Emitting Diodes

Bismuth oxide photocatalysts were synthesized and coated on the front surface of phosphor-converted white light-emitting diodes to produce a safe and environmentally benign lighting source. Bismuth oxide photocatalyst powders were synthesized with a spray pyrolysis method at 500°C, 600°C, 700°C, and 800°C. Using the absorption spectrum in the blue and UV regions of the bismuth oxide photocatalysts, the blue light and UV leakage problems of phosphor-converted white LEDs can be significantly reduced. The experimental results showed that bismuth oxide photocatalyst synthesized at 700°C exhibited the most superior spectrum inhibiting ability. The suppressed ratio reached 52.33% in the blue and UV regions from 360 to 420 nm. Related colorimetric parameters and the photocatalyst decomposition ability of fabricated white-light LEDs were tested. The CIE chromaticity coordinates(x,y)were (0.349, 0.393), and the correlated color temperature was 4991 K. In addition, the coating layer of photocatalyst can act as an air purifier and diffuser to reduce glare. A value of66.2±0.60 ppmv of molecular formaldehyde gas can be decomposed in 120 mins.

scholarly journals Single-Component White Light Emitting CdSexSy Alloy Nanocrystals Through Phosphine-Free Route

2020 ◽  
Author(s):  
Shilpi Jaiswal ◽  
Jyotsana Pathak ◽  
Abhijit Patra
Keyword(s):  
Quantum Yield ◽  
White Light ◽  
Light Emission ◽  
Semiconductor Nanocrystals ◽  
White Light Emission ◽  
Molar Ratio ◽  
Visible Range ◽  
One Pot ◽  
Light Emitting ◽  
Hydrogel Matrix

Semiconductor nanocrystals are promising for display and lighting devices. Herein, we report a facile one-pot synthetic route to fabricate white light emitting CdSexSy nanocrystals with enhanced quantum yield using CdO, S powder, and Se powder as precursors. The phosphine-free route was adopted, employing paraffin oil as the reducing agent and solvent for the fabrication. The optical properties can be effectively tailored by controlling the reaction time and the molar ratio of Se/S. The emission of pristine CdSexSy nanocrystals covered a broad visible range from 400 to 750 nm. The CdSexSy nanocrystals (Se/S = 0.4) exhibited white-light emission with quantum yield of 50 ± 3 % and Commission Internationale de l'Eclairage (CIE) chromaticity coordinates of (0.30, 0.31). The band-edge (~400-450 nm) to trap-state (~550-750 nm) emissions was tuned by controlling the Se/S ratio, and the different shades of white light were obtained. Furthermore, the quantum yield and CIE coordinates of the CdSexSy nanocrystals (Se/S = 0.4) were found to be similar even after 30 days of fabrication, showing the high stability of nanocrystals. The white light emission was retained in nanocrystals-embedded poly(methyl methacrylate) (PMMA) thin film and also in the hydrogel matrix. The one-pot, low-cost, scalable fabrication of white light emitting CdSexSy nanocrystals demonstrated in the present study offers promising scope in the solid-state display applications. <br>

scholarly journals Optimization of LaPO4:Bi3+ Single-Phased White-Emitting Phosphor Luminescence Properties by Li+/Na+ Doping

2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Taoli Deng ◽  
Qiuyun Zhang
Keyword(s):  
White Light ◽  
Host Lattice ◽  
X Ray Diffraction ◽  
Solid State Reaction Technique ◽  
Conventional Solid State Reaction ◽  
Light Emitting ◽  
Chromaticity Coordinate ◽  
Na Doping ◽  
Single Host ◽  
Cie Chromaticity

LaPO4:Bi3+ single-phased white-emitting phosphors doped with both Li+/Na+ ions were successfully prepared by a conventional solid-state reaction technique. Microstructures were analyzed by both X-ray diffraction and high-resolution scanning electron microscopy experiments. Under the excitation of 335 nm, the La0.97PO4:Bi3+0.03 phosphor showed four emission bands with maxima at 460 nm, 487 nm (blue), 530 nm (yellow), and 637 nm (red); these can be successfully combined to form pure white light in a single host lattice only by simple activator Bi3+ ion. It was found that changing the concentration of dopant (Li+, Na+ ions) did not produce a change in shape or location of the emission peaks, but the value of the emission intensity increased; this was particularly evident in the red emission, which could optimize the white light emitting performance of the phosphors. When the Na+ doping concentration was 0.02, the CIE chromaticity coordinate of phosphor La0.95PO4:Bi3+0.03, Na+0.02 was (0.3008, 0.3203), close to that of the standard white light.

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.

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