scholarly journals Applying calcium fluoride and silica particles: A solution to improve color homogeneity of pc-WLEDS

2021 ◽  
Vol 11 (5) ◽  
pp. 3864
Author(s):  
Huu Phuc Dang ◽  
Nguyen Thi Phuong Loan ◽  
Thanh Tung Nguyen ◽  
Sang Dang Ho
Keyword(s):  
Calcium Fluoride ◽  
Scattering Theory ◽  
Mie Scattering ◽  
Luminous Flux ◽  
Luminous Efficiency ◽  
Color Temperature ◽  
Yellow Phosphor ◽  
Scattering Coefficients ◽  
Important Quality ◽  
Mie Scattering Theory

<span>This article focuses on enhancing the lighting efficiency of pc-WLEDs, a new and advanced lighting solution that has received lots of attention. To adapt to the demand of modern lighting, the lighting performance of pc-WLEDs must be improved, especially the color homogeneity and luminous flux, two of the most important quality indicators of pc-WLEDs. Through experiments, this article proposes using the scattering enhancement particles (SEPs) such as CaF<sub>2 </sub>and SiO<sub>2 </sub>with yellow phosphor Y<sub>3</sub>Al<sub>5</sub>O<sub>12</sub>:Ce<sup>3+</sup> in pc-WLEDs configuration. The pc-WLEDs model is created by using the LightTools program and set at 8500 K correlated color temperature, while the experimental results yielded from this simulation will be verified by Mie-scattering theory. The information from this article reveals the scattering coefficients of SEPs at 455 nm and 595 nm wavelengths. Moreover, it is confirmed that the employment of CaF<sub>2 </sub>is effective in promoting the color but may damage the luminous efficiency if the concentration is too high while the SEP material, SiO<sub>2</sub>, exhibits high luminous efficiency at all concentration.</span>

scholarly journals The Application of Calcium Carbonate CaCO3 and Titania TiO2 for Color Homogeneity and Luminous Flux Enhancement in PC-LEDs

2021 ◽  
Vol 5 (2) ◽  
pp. 75
Author(s):  
Viet Tien Pham ◽  
Ngoc Hung Phan ◽  
Guo-Feng Luo ◽  
Hsiao-Yi Lee ◽  
Doan Quoc Anh Nguyen
Keyword(s):  
Anisotropic Scattering ◽  
Mie Scattering ◽  
Luminous Flux ◽  
Color Temperature ◽  
Optical Simulation ◽  
Development Method ◽  
Scattering Coefficients ◽  
Creative Commons ◽  
Mie Scattering Theory ◽  
Open Access Article

This article studies the development method of pc-LED, a phosphor-converted lighting emitting diode, with scattering enhancement particles (SEPs) at 7000 K correlated color temperature. The pc-LED is an advanced lighting solution that has been applied in many different categories; nonetheless, to keep up with the demands of modern lighting, the pc-LEDs need to enhance the color homogeneity and luminous flux. The detailed experiments on the two SEPs used in the articles are also presented. The experiments include combining each of these SEPs with a yellow phosphor Y3Al5O12:Ce3+ to test their properties and influences on the lighting of pc-LEDs. The scattering coefficients, the anisotropic scattering, the reduced scattering, and the scattering amplitudes at 450 nm and 550 nm are the subjects of SEPs study. The LightTools program is used to create the simulation of pc-LED, the results of the optical simulation will then be verified with the Mie-scattering theory. The findings of the research conclude that TiO2 particles are the best for the growth of color homogeneity while CaCO3 particles are effective in limiting the color deviation in correlated color temperature. Even though the SEPs benefit the lighting performance, their concentration must be managed to be under an acceptable amount to ensure desired results and avoid unwanted damages.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.

scholarly journals The effectiveness of MgCeAl11O19:Tb3+ phosphor in enhancing the luminous efficacy and color quality of multi-chip white LEDs

2020 ◽  
Vol 10 (5) ◽  
pp. 4631
Author(s):  
Nguyen Thi Phuong Loan ◽  
Nguyen Doan Quoc Anh
Keyword(s):  
Optical Properties ◽  
Mie Scattering ◽  
Luminous Flux ◽  
Color Temperature ◽  
White Leds ◽  
Color Quality ◽  
Supporting Material ◽  
Mie Scattering Theory ◽  
Led Lights

In this research paper, we introduced yellow-green MgCeAl11O19:Tb3+ asa new phosphor ingredient to adapt to the quality requirements onthe chromatic homogeneity and emitted luminous flux of modern multi-chip white LED lights (MCW-LEDs). The results from experiments and simulation show that employing MgCeAl11O19:Tb3+ phosphor can lead to much better optical properties and therefore is a perfect supporting material to achieve the goals of the research. When the MgCeAl11O19:Tb3+ phosphor is added into the phosphorus composite which already contains YAG: Ce3+ particles, and the silicone glue, it affects the optical properties significantly. In other words, the concentration of this phosphor can determine the efficiency of lumen output and chromatic homogeneity of WLEDs. In specific, as the concentration of MgCeAl11O19:Tb3+ go up, the luminous yield will increase accordingly, though there is an insignificant decrease in CQS. Moreover, if the MgCeAl11O19:Tb3+ concentration reduce a little bit, it is possible to better the correlated color temperature uniformity and lumen efficacy of LED packages. In addition, the Mie scattering theory, Monte Carlo simulation and LightTools 8.3.2 software are employed to analyze and simulate the LED packages’ structure as well as the phosphor compound.

scholarly journals Predicted Light Scattering from Particles Observed in Human Age-Related Nuclear Cataracts Using Mie Scattering Theory

2007 ◽  
Vol 48 (1) ◽  
pp. 303 ◽  
Author(s):  
M. Joseph Costello ◽  
So¨nke Johnsen ◽  
Kurt O. Gilliland ◽  
Christopher D. Freel ◽  
W. Craig Fowler
Keyword(s):  
Light Scattering ◽  
Scattering Theory ◽  
Mie Scattering ◽  
Age Related ◽  
Mie Scattering Theory

Simulation and Calculation of 10.6μm Laser Time Broadening and Space Broadening Characteristics in Near-Earth Dust

2013 ◽  
Vol 401-403 ◽  
pp. 437-440 ◽  
Author(s):  
Ni Chen Yang ◽  
Hong Xia Wang ◽  
You Zhang Zhu
Keyword(s):  
Monte Carlo ◽  
Time Delay ◽  
Size Distribution ◽  
Scattering Theory ◽  
Mie Scattering ◽  
Dust Particles ◽  
Distribution Model ◽  
Laser Scattering ◽  
Transmission Distance ◽  
Mie Scattering Theory

Based on the Mie scattering theory and the gamma size distribution model, 10.6μm laser scattering characteristics in dust particles are calculated and analyzed.On this basis,the time broadening and space broadening characteristics of the laser are analyzed by using Monte Carlo method.Transmittance change with the transmission distance are quantitative calculated and the time detention and space broadening characteristics of the laser passed through dust for different transmission distances are calculated and analyzed. The results show that the transmittance decreases with increasing transmission distance, and the transmittance is close to 0 when transmission distance is close to 200m; The time delay of 10.6μm laser is more significant with the increaseing transmission distance; The space broadening of 10.6μm laser is more obvious and the energy is more dispersed with the increaseing transmission distance.

Mie Scattering Theory for Phonon Transport in Particulate Media

2004 ◽  
Vol 126 (5) ◽  
pp. 793-804 ◽  
Author(s):  
Ravi S. Prasher
Keyword(s):  
Cross Section ◽  
Scattering Theory ◽  
Mode Conversion ◽  
Mie Scattering ◽  
Phonon Transport ◽  
Scattering Cross Section ◽  
Particulate Media ◽  
Scattering Cross ◽  
Transport Cross Section ◽  
Mie Scattering Theory

Scattering theory for the scattering of phonons by particulate scatterers is developed in this paper. Recently the author introduced the generalized equation of phonon radiative transport (GEPRT) in particulate media, which included a phase function to account for the anisotropic scattering of phonons by particulate scatterer. Solution of the GEPRT showed that scattering cross section is different from the thermal transport cross-section. In this paper formulations for the scattering and transport cross section for horizontally shear (SH) wave phonon or transverse wave phonon without mode conversion is developed. The development of the theory of scattering and the transport cross section is exactly analogous to the Mie scattering theory for photon transport in particulate media. Results show that transport cross section is very different from the scattering cross section. The theory of phonon scattering developed in this paper will be useful for the predictive modeling of thermal conductivity of practical systems, such as nanocomposites, nano-micro-particle-laden systems, etc.

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