scholarly journals Color-tunable white-light of binary tris-β-diketonate-(Dy3+, Gd3+ ) complexes’ blend under single wavelength excitation

2020 ◽  
Author(s):  
Qi Shi
Keyword(s):  
Solid State ◽  
Blue Light ◽  
White Light ◽  
Mixed Complex ◽  
Yellow Light ◽  
Color Tuning ◽  
Color Tunable ◽  
Fluorescence Titrations

Based on the Dy³⁺-centered yellow-light and the ligands-based blue-light of the iso-structural two complexes [Ln(acac)3(5-Br-2,2′-bpy)] (Ln³⁺ = Dy³⁺ (2) or Gd³⁺ (3); Hacac = acetylacetone, 5-Br-2,2′-bpy = 5-bromo-2,2′-bipyridine), respectively, the stoichiometric fluorescence titrations of their tris-β-diketonate-(Dy³⁺, Gd³⁺x)-mixed complex, show that it is capable of the smooth color-tuning (yellow- to white- and to blue-light) under single wavelength excitation. Moreover, through the dichromatic integration, the binary tris-β-diketonate-(Dy³⁺, Gd³⁺x) complex exhibits the straightforward white-light in solid-state.

Improved Yellow Light Emission in the Achievement of Dichromatic White Light Emitting Diodes

2013 ◽  
Vol 1538 ◽  
pp. 371-375
Author(s):  
Zhao Si ◽  
Tongbo Wei ◽  
Jun Ma ◽  
Ning Zhang ◽  
Zhe Liu ◽  
...  
Keyword(s):  
Blue Light ◽  
White Light ◽  
Light Emitting Diodes ◽  
Light Emission ◽  
Dual Wavelength ◽  
Emission Wavelength ◽  
White Led ◽  
Yellow Light ◽  
Light Emitting ◽  
White Light Emitting Diodes

ABSTRACTA study about the achievement of dichromatic white light-emitting diodes (LEDs) was performed. A series of dual wavelength LEDs with different last quantum-well (LQW) structure were fabricated. The bottom seven blue light QWs (close to n-GaN layer) of the four samples were the same. The LQW of sample A was 3 nm, and that of sample B, C and D were 6 nm, a special high In content ultra-thin layer was inserted in the middle of the LQW of sample C and on top of that of sample D. XRD results showed In concentration fluctuation and good interface quality of the four samples. PL measurements showed dual wavelength emitting, the blue light peak position of the four samples were almost the same, sample A with a narrower LQW showed an emission wavelength much shorter than that of sample B, C, D. EL measurement was done at an injection current of 100 mA. Sample A only showed LQW emission due to holes distribution. Because of wider LQW, the emission wavelength of sample B, C and D was longer and peak intensity was weaker. Sample D with insert layer on top of LQW showed strongest yellow light emission with a blue peak. As the injection current increased, sample A showed highest output light power due to narrower LQW. Of the other three samples with wider LQW, sample D showed highest output power. Effective yellow light emission has always been an obstacle to the achievement of dichromatic white LED. Sample D with insert layer close to p-GaN can confine the hole distribution more effectively hence the recombination of holes and electrons was enhanced, the yellow light emission was improved and dichromatic white LED was achieved.

scholarly journals Towards Multi-Functional SiO2@YAG:Ce Core–Shell Optical Nanoparticles for Solid State Lighting Applications

Nanomaterials ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 153 ◽  
Author(s):  
Mahdi Kiani Khouzani ◽  
Abbas Bahrami ◽  
Maryam Yazdan Mehr ◽  
Willem Dirk van Driel ◽  
Guoqi Zhang
Keyword(s):  
Optical Properties ◽  
Solid State ◽  
White Light ◽  
Sio2 Nanoparticles ◽  
Solid State Lighting ◽  
Core Shell ◽  
Yellow Light ◽  
Shell Nanoparticles ◽  
X Ray ◽  
Core Shell Nanoparticles

This paper aims to investigate the synthesis, structure, and optical properties of SiO2@YAG:Ce core–shell optical nanoparticles for solid state lighting applications. YAG:Ce phosphor is a key part in white light emitting diodes (LEDs), with its main functionality being the generation of yellow light. Generated yellow light from phosphor will be combined with blue light, emitted from chip, resulting in the generation of white light. Generated light in LEDs will often be scattered by SiO2 nanoparticles. SiO2 nanoparticles are often distributed within the optical window, aiming for a more homogeneous light output. The main idea in this research is to combine these functionalities in one core–shell particle, with its core being SiO2 and its shell being phosphor. In this study core–shell nanoparticles with different Ce3+ concentrations were synthesized by a sol–gel method. Synthesized nanoparticles were characterized by X-ray diffraction (XRD), small angle X-ray scattering (SAXS) analysis, high resolution transmission electron macroscopy (HRTEM), Fourier transform infrared (FTIR), and photoluminescence spectroscopy. Luminescence characteristics of SiO2@YAG:Ce core–shell particles were compared with that of SiO2/YAG:Ce mixture composite, which is now used in commercial LEDs. Obtained results showed that core–shell nanoparticles have comparatively much better optical properties, compared to SiO2/YAG:Ce mixture composite and can therefore be potentially used in LEDs.

scholarly journals Effect of colour of light on the opening of inflorescence buds and post-harvest longevity of pot chrysanthemums (Chrysanthemum × grandiflorum (Ramat.) Kitam)

2012 ◽  
Vol 64 (3) ◽  
pp. 13-18 ◽  
Author(s):  
Marek Jerzy ◽  
Piotr Zakrzewski ◽  
Anita Schroeter-Zakrzewska
Keyword(s):  
Blue Light ◽  
Significant Influence ◽  
White Light ◽  
Red Light ◽  
Green Light ◽  
Fluorescent Light ◽  
Yellow Light ◽  
Post Harvest ◽  
Growth Room

The pot cultivar of <i>Chrysanthemum</i> × <i>grandiflorum</i> 'Leticia Time Yellow' was cultivated and stored in a growth room under fluorescent light of white, blue, green, yellow and red colour. Quantum irradiance was 30 μmol · m<sup>-2</sup> × s<sup>-1</sup>. The colour of light exerted a significant influence on the opening of closed inflorescence buds and on post-harvest longevity of pot chrysanthemums grown earlier in an unheated plastic tunnel. Under florescent lamps emitting blue light at a wavelength of 400-580 nm, inflorescence buds opened and coloured the earliest. The number of developed flower heads was the greatest under blue and white light. Flower heads developing in blue light were bigger than flower heads developing in white and green light. In red light at a wavelength of 600-700 nm, plants flowered latest and they produced the smallest flower heads. Post-harvest longevity was preserved longest in chrysanthemums kept under blue, white and green light. In red and yellow light, the flowers were overblown earliest.

scholarly journals Effects of light qualities on growth, lipid contents and fatty acids profiles of Cylindrotheca closterium

2021 ◽  
Author(s):  
Congying Zhang Zhang ◽  
Ruibing Peng ◽  
Yi Wu ◽  
Zhihong Wu ◽  
Zuhao Zhang ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Blue Light ◽  
White Light ◽  
Growth Rates ◽  
Light Quality ◽  
Green Light ◽  
Total Lipids ◽  
Yellow Light ◽  
Cylindrotheca Closterium ◽  
Lipid Contents

Abstract Background Marine diatoms were considered as a promising alternative to microbial resources for the development of biofuels, food additives, medicines and chemical materials. Light of wavelength is a principal element that can easily be controlled in microalgal scale-culture and influence the growth, pigment composition, and lipids accumulation of algal cells. With the increasing implementation of light-emitting diodes (LEDs) in microalgal production systems (photobioreactors), a measure of light quality controlled by LED could be suitable to improve microalgal yields. Results In this study, Cylindrotheca Closterium, a widely used diatom, influenced by five light quality (white, red, blue, green and yellow light) was tested for its effects of growth rates, chlorophylls contents, total lipids contents and fatty acids compositions. The growth and chlorophyll experiments also showed that the green and yellow light significantly improve the growth rates and chlorophylls contents than other groups (P < 0.05). The group white light showed the greatest increases in total lipid contents of C. closterium (P < 0.05). The group blue light had the highest polyunsaturated fatty acids (PUFAs) proportion (P < 0.05), while the group white showed the lowest PUFAs and the highest saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs) proportions (P < 0.05). The proportions of SFAs and MUFAs were negatively correlated with growth, chlorophylls, and lipids. And the proportion of PUFAs and n-3 PUFA was positively correlated with growth chlorophylls, and lipids. Principal component analysis showed that the fatty acid composition differed among light quality groups. Conclusion In summary, green light and yellow light were conductive to boosting the growth and chlorophylls accumulation of C. closterium. White light increased total lipid yields, while blue light was superior in increasing the production of unsaturated fatty acids, especially on the timnodonic acid (EPA). The application of two-step methods to increase the production of biomass and fatty acids is an effective measure for the cultivation of C. closterium; green light is used to increase the growth, followed by white light cultivation to improve total lipids or blue light to enhance the proportion of PUFAs of C. closterium.

Solid-State Encapsulation and Color Tuning in Films of Cesium Lead Halide Perovskite Nanocrystals for White Light Generation

2019 ◽  
Vol 2 (3) ◽  
pp. 1185-1193 ◽  
Author(s):  
Ilker Torun ◽  
Yemliha Altintas ◽  
Ahmet Faruk Yazici ◽  
Evren Mutlugun ◽  
M. Serdar Onses
Keyword(s):  
Solid State ◽  
White Light ◽  
Color Tuning ◽  
Perovskite Nanocrystals ◽  
White Light Generation ◽  
Light Generation ◽  
Halide Perovskite ◽  
Lead Halide

A novel blue light pumped yellow-emitting phosphor RbZnPO4:Dy3+ with satisfactory color tuning and thermal properties for high-power warm white light emitting diodes

RSC Advances ◽  
2015 ◽  
Vol 5 (129) ◽  
pp. 106795-106799 ◽  
Author(s):  
Ge Zhu ◽  
Shuangyu Xin
Keyword(s):  
Thermal Properties ◽  
Blue Light ◽  
White Light ◽  
High Power ◽  
Color Tuning ◽  
Light Emitting ◽  
Yellow Phosphor ◽  
White Leds ◽  
Warm White Light ◽  
White Light Emitting Diodes

Novel yellow phosphor RbZnPO4:Dy3+ with satisfactory color tuning and thermal properties for high-power white LEDs.

Elucidating white light emissions in Tm3+/Dy3+ codoped polyoxometalates: a color tuning and energy transfer mechanism study

2018 ◽  
Vol 47 (39) ◽  
pp. 13949-13956 ◽  
Author(s):  
Hechen Wu ◽  
Minna Zhi ◽  
Vikram Singh ◽  
Huafeng Li ◽  
Pengtao Ma ◽  
...  
Keyword(s):  
Energy Transfer ◽  
White Light ◽  
Transfer Mechanism ◽  
Energy Transfer Mechanism ◽  
Mechanism Study ◽  
Color Tuning ◽  
Color Tunable

A series of isomorphic Tm3+/Dy3+ codoped POM derivatives were successfully synthesized and characterized, and color-tunable emissions and the energy transfer mechanism have been studied.

scholarly journals Rangsangan Warna Cahaya terhadap Prosentase Karkas Ayam Kampung Super

2021 ◽  
Vol 4 (1) ◽  
pp. 73-78
Author(s):  
Idrus Umar
Keyword(s):  
Blue Light ◽  
White Light ◽  
Red Light ◽  
Green Light ◽  
Carcass Weight ◽  
Yellow Light ◽  
Average Value ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Light Color

The purpose of the study was to determine the effect of giving different colors of light on carcass percentage and carcass weight in Kampung Super chickens. The research design used was a completely randomized design (CRD). A total of 80 Kampung Super chickens were used in this study. The research treatments were P1 (white light color), P2 (yellow light color), P3 (green light color), P4 (red light color), P5 (blue light color). The results of the study of the highest carcass presentation were found in the treatment that was given red light with an average value of 62.455%. The highest carcass weight was found in the same treatment, which was given a red light with an average value of 674.75 g/head. The provision of different light colors did not have a significant effect on the carcass percentage and carcass weight of the finisher phase super free-range chicken. 

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