An optical-thermal model for laser-excited remote phosphor with thermal quenching

Ma, Yupu; Lan, Wei; Xie, Bin; Qiu, Cheng‐Wei; Luo, Xiaobing

doi:10.1016/j.ijheatmasstransfer.2017.09.066

Cited by 108 publications

(31 citation statements)

References 32 publications

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“…[46] Laser Photonics Rev. 2019, 13 The same decay behavior of the LSN:Ce powder and the PiG film shown in Figure 6b again confirms that the optical properties of LSN:Ce are not affected by the glass matrix. Thermal performance is of vital importance for the color conversion materials used in high-power laser lighting.…”

Section: Photoluminescence Thermal Quenching and Durabilitysupporting

confidence: 67%

“…But, it suffers from a low light absorption and a bad light uniformity due to the absence of scattering Laser Photonics Rev. 2019, 13,1800216 C 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim centers. Park et al prepared a YAG:Ce single crystal for laser lighting, which has a lower external quantum efficiency (EQE) of only 47% than that of the powder form (80%).…”

Section: Introductionmentioning

confidence: 99%

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A Thermally Robust La₃Si₆N₁₁:Ce‐in‐Glass Film for High‐Brightness Blue‐Laser‐Driven Solid State Lighting

You

Zheng

et al. 2018

Laser & Photonics Reviews

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Color converter is a key luminescent material in the laser‐driven solid state lighting, which must bear high‐density excitation and serious thermal attack from the incident laser. Here, a thermally robust yellow‐emitting La3Si6N11:Ce‐in‐glass (LSN:Ce‐PiG) film for laser lighting is reported by co‐firing the LSN:Ce and glass powders on a thermally conductive sapphire substrate. No detectable interfacial reaction occurs between the LSN:Ce particle and glass matrix, enabling the film to fully inherit the original thermal robustness and high quantum efficiency. The optical performance of LSN:Ce‐PiG‐converted white laser light has been effectively optimized by changing the phosphor‐to‐glass (PtG) ratio and the film thickness. The highest light conversion efficiency is respectively achieved at PtG = 2:3 and the thickness of 70 µm, and the saturation threshold is found to decrease with either a higher PtG ratio or a thicker film. The optimized LSN:Ce‐PiG film (P2G3‐50) can withstand a maximum laser power density of 12.91 W mm−2 and produce a cool white light with a high luminous flux of 1076 lm (luminance of 773 Mcd m−2), a luminous efficiency of 166.05 lm W−1, a color rendering index of 70. These results make the LSN:Ce‐PiG film a considerably promising color converter for laser lighting.

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Section: Photoluminescence Thermal Quenching and Durabilitysupporting

confidence: 67%

Section: Introductionmentioning

confidence: 99%

A Thermally Robust La₃Si₆N₁₁:Ce‐in‐Glass Film for High‐Brightness Blue‐Laser‐Driven Solid State Lighting

You

Zheng

et al. 2018

Laser & Photonics Reviews

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“…Considering the refractive index mismatch of the phosphor layer and the surrounding air, light will be specularly reflected back into the layer when attempting to travel out through the phosphor-air boundary [29,31]. However, in previous models [12][13][14][15][16][17], the refractive indexes of the phosphor and the air are considered identical and equal to one. In this context, light will travel through the layer without deflection and the obtained angular intensity distribution may be misleading.…”

Section: Model Definitionmentioning

confidence: 99%

“…It is hard to observe the internal light propagation properties by experiments. Researchers have turned to developing theoretical and numerical methods to model the phosphor, including the Monte-Carlo ray-tracing simulations [2,[6][7][8], the diffusion-approximation (DA) method [9,10], and a simplified one-dimensional model based on an extended Kubelka-Munk (KM) theory for fluorescence [11][12][13][14][15][16][17]. Monte-Carlo simulations can model the phosphor with high accuracy, but it often takes plenty of computational time and resources because usually a million rays need to be traced to get accurate results [18].…”

Section: Introductionmentioning

confidence: 99%

Phosphor modeling based on fluorescent radiative transfer equation

Wang

Sun

et al. 2018

Opt. Express

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The behaviors of the light propagation in the phosphor play a vital role in determining the optical performance of the phosphor-converted light-emitting diodes (pc-LEDs). In this paper, we presented a general model based on the radiative transfer equation integrated with fluorescence (FRTE) to describe the overall light propagating properties in the phosphor layer in terms of light absorption, strong forward scattering, and fluorescence. The model was established by accounting for general boundary conditions including the LED Lambertian incidence, the diffuse reflection at the substrate/reflector, and the Fresnel reflection at the phosphor-air interface. The spectral element method (SEM) was extended to numerically solve FRTE. The radiant intensity at any location and direction of blue and yellow light was iteratively calculated, in which case the angular properties could be further evaluated. The model was validated by comparing the light extraction efficiency (LEE) and angular correlated color temperature (CCT) calculated by the presented model with the experimental results. Good agreements were achieved between model predictions and measurements with the corresponding maximum deviation of 4.9% and 3.7% for LEE and CCT, respectively. We also conducted a comparison between our model and the previous Kubelka-Munk (KM) theory. It has been revealed that the KM theory may overestimate the phosphor heating due to lacking of the blue light scattering effect.

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“…The main focus of most other reported investigations has been on modeling the thermal distribution in the phosphor to limit saturation [2,17,18]. One attempt to limit thermal quenching was reported by Ma et al with simulation of the temperature distribution and experimental verification [19]. In a recent reporting, Zhang et al investigated the impact of scattering on the luminescent spot [20].…”

Section: Introductionmentioning

confidence: 99%

Limitations to emission spot size in laser lighting

Jensen

Krasnoshchoka

Hansen³

et al. 2020

Light-Emitting Devices, Materials, and Applications XXIV

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Laser lighting is an emerging technology to generate high luminance lighting. To achieve high luminance or high luminous exitance, the light emitter must have high flux and small size simultaneously. When laser light is focused to a small spot size on the phosphor material, the two main limitations are saturation of the phosphor material and the spot size of the generated light. Here, we investigate experimentally and numerically the spot size of laser lighting dependent on the spot size of the incident laser light and the material properties of the wavelength converting phosphor material. We find numerically that the spot size of the generated white light is significantly influenced by the phosphor properties. The spot size of the white light determines the étendue and thereby the possibility to collect and shape the light. This has important implications in applications of laser lighting.

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An optical-thermal model for laser-excited remote phosphor with thermal quenching

Cited by 108 publications

References 32 publications

A Thermally Robust La₃Si₆N₁₁:Ce‐in‐Glass Film for High‐Brightness Blue‐Laser‐Driven Solid State Lighting

A Thermally Robust La₃Si₆N₁₁:Ce‐in‐Glass Film for High‐Brightness Blue‐Laser‐Driven Solid State Lighting

Phosphor modeling based on fluorescent radiative transfer equation

Limitations to emission spot size in laser lighting

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An optical-thermal model for laser-excited remote phosphor with thermal quenching

Cited by 108 publications

References 32 publications

A Thermally Robust La3Si6N11:Ce‐in‐Glass Film for High‐Brightness Blue‐Laser‐Driven Solid State Lighting

A Thermally Robust La3Si6N11:Ce‐in‐Glass Film for High‐Brightness Blue‐Laser‐Driven Solid State Lighting

Phosphor modeling based on fluorescent radiative transfer equation

Limitations to emission spot size in laser lighting

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Product

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About

A Thermally Robust La₃Si₆N₁₁:Ce‐in‐Glass Film for High‐Brightness Blue‐Laser‐Driven Solid State Lighting

A Thermally Robust La₃Si₆N₁₁:Ce‐in‐Glass Film for High‐Brightness Blue‐Laser‐Driven Solid State Lighting