Improving the CRI of Al2O3-YAG:Ce eutectic for high-power white LEDs applications: Energy-transfer and co-luminescence

Lü, Hao; Song, Qingsong; Xu, Xiaodong; Liu, Peng; Liu, Jian; Xu, Jie; Tao, Xiaohua; Wang, Jun; Bian, Kaiting; Li, Wen; Zhang, Yan

doi:10.1016/j.optmat.2021.111415

Cited by 11 publications

(9 citation statements)

References 35 publications

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“…In 2021, Lu et al [ 60 ] prepared Ce 3+ and Cr 3+ co-doped Al 2 O 3 -YAG eutectics through the micro-pulling-down method. X-ray diffraction (XRD) and scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS) results showed substitution of Y 3+ with Ce 3+ and occupation of octahedral Al 3+ sites by Cr 3+ .…”

Section: Co-doping Red-emitting Cr 3+ Pr ...mentioning

confidence: 99%

Recent Advances in Preparing Transparent Phosphor Ceramics for High-Index Color Rendering and High-Power Lighting

Du,

Li,

Zhang

et al. 2024

Molecules

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In recent years, high-power white light-emitting diode (wLED)/laser diode (wLD) lighting sources based on transparent phosphor ceramic (TPC) materials have attracted increasing application interest in automotive headlights, projection displays, and space navigation lighting due to their superior brightness, lighting distance, compactness, lifespan, and environmental resistance compared with the widely used phosphor-converted wLEDs. However, preparing TPC-converted wLEDs/wLDs with high color rendering index (CRI) remains a huge challenge, which limits their widespread application. In this review, we summarize the recently adopted strategies for constructing TPCs to develop high-power wLEDs/wLDs with high CRI values (>75). The construction protocols were categorized into four groups: host regulation, red-emitter doping, host regulation/red-emitter doping combination, and composite structure design. A comprehensive discussion was conducted on the design principles, photoluminescent properties, and device performances for each strategy. The challenges and future trends of high-power and high-CRI wLEDs/wLDs based on TPCs are also discussed toward the end of this review.

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Section: Co-doping Red-emitting Cr 3+ Pr ...mentioning

confidence: 99%

Recent Advances in Preparing Transparent Phosphor Ceramics for High-Index Color Rendering and High-Power Lighting

Du,

Li,

Zhang

et al. 2024

Molecules

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“…Compared with phosphors and phosphor glasses, Ce:YAG phosphor ceramics possess unique advantages and potentials, which have excellent thermal properties, good mechanical properties, and high chemical stability, as well as the advantages of adjustable microstructure and simple preparation process 7–10 . However, the pure‐phase Ce:YAG phosphor ceramics face the problems of low blue light absorption efficiency and low thermal conductivity (9–14 W m −1 K −1 ), resulting in low luminous efficiency and thermal quenching with increasing blue LD power density for solid‐state lighting application 11,12 …”

Section: Introductionmentioning

confidence: 99%

“…[7][8][9][10] However, the pure-phase Ce:YAG phosphor ceramics face the problems of low blue light absorption efficiency and low thermal conductivity (9-14 W m −1 K −1 ), resulting in low luminous efficiency and thermal quenching with increasing blue LD power density for solid-state lighting application. 11,12 The effective strategy of adding the second-phase Al 2 O 3 as the scattering center in Ce:YAG phosphor ceramics has been proven to improve the luminous efficiency and the luminescence uniformity. [13][14][15][16] Moreover, the addition of Al 2 O 3 , having a higher thermal conductivity of 32-35 W m −1 K −1 at room temperature, can improve the thermal conductivity of Al 2 O 3 -Ce:YAG composite phosphor ceramics (CPCs).…”

Section: Introductionmentioning

confidence: 99%

Al₂O₃–Ce:YAG composite phosphor ceramics for white laser lighting: Novel preparation and regulatable properties

et al. 2023

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In this work, a series of Al2O3–Ce:YAG phosphor powders were synthesized by regulating the excess Al3+ of (Y,Ce)3Al5O12 via coprecipitation method for the first time, where Al3+, Ce3+, and Y3+ elements were uniformly distributed. With the increase of Al3+ content, the morphology of the powders changed from wormlike shapes to flaky shapes, and Y3Al5O12 phases had a tendency to convert to YAlO3 phases. The x wt.% Al2O3–(Y0.999Ce0.001)3Al5O12 (x = 20, 30, 40, 50, 60, and 70) composite phosphor ceramics (CPCs) were obtained by vacuum sintering (1775°C × 10 h), where Al2O3 and Ce:YAG phases were also well‐distributed. When the Al2O3 content was 30–40 wt.%, the average grain size of Al2O3 was close to that of Ce:YAG. A solid‐state laser lighting device was constructed by a 450 nm laser source and CPCs in a reflection mode. By adjusting the laser power, the correlated color temperature (CCT) values of white laser diodes (LDs) were achieved close to the standard white light of 6500 K. Impressively, the white LDs equipped with the 40 wt.% Al2O3‐containing CPCs showed the optimum CCT of 6498 K (color coordinates: 0.31 and 0.38), as well as a high luminous flux of 1169 lm and efficiency of 166 lm/W at the LD power of 7.05 W. This work has provided a potential idea to optimize the composition uniformity of Al2O3–Ce:YAG CPCs as also to explore their excellent performance in the application of white laser lighting.

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“…The abovementioned phosphors and PCs both usually focused on reaching high R a , while the R 9 was neglected or failed to offer due to R 9 < 0 in hp-LEDs. 33 To meet the requirement of hp-LEDs with high CRI (R a and R 9 ), a single-structured and multi-color emission PCs as well as good thermal stability should be exploited. Based on the fine properties of LuAG-based ceramic, the ions substitution strategy of co-doping Ce 3+ and Mn 2+ was proposed to prepare single-structured LuAG:Ce,Mn PCs for hp-LEDs application.…”

Section: Introductionmentioning

confidence: 99%

“…For example, the LED light of medical endoscope requires that the R 9 is large enough to see blood vessels clearly. The above‐mentioned phosphors and PCs both usually focused on reaching high R a , while the R 9 was neglected or failed to offer due to R 9 < 0 in hp‐LEDs 33 …”

Section: Introductionmentioning

confidence: 99%

A single‐structured LuAG:Ce,Mn phosphor ceramics with high CRI for high‐power white LEDs

et al. 2022

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The realization of high color rendering index (CRI) is still a great challenge for high‐power LEDs (hp‐LEDs), which is hindered by the phosphor converter. In this work, based on the strategy of Ce3+ and Mn2+ multi‐ion substitution, the single‐structured LuAG:Ce,Mn ceramics with high CRI were prepared via regulating the ratio of tri‐color (red, green, and blue) components. The effects of Mn2+‐Si4+ pairs doping content on the crystal structure, morphologies, and luminescence properties were investigated in detail. The red emission centered at 590 and 750 nm were effectively compensated by regulating Mn2+ occupancy sites, resulting in a significant improvement of CRI. Pure white light with general CRI Ra up to 91.0, special CRI R9 reaching 37.9 and LE as high as 85.07 lm/W was achieved, when the hp‐LEDs were constructed from related phosphor ceramic Ce02Mn7. These results suggest that the LuAG:Ce,Mn phosphor ceramics are highly promising color converters for hp‐LEDs application.

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Improving the CRI of Al2O3-YAG:Ce eutectic for high-power white LEDs applications: Energy-transfer and co-luminescence

Cited by 11 publications

References 35 publications

Recent Advances in Preparing Transparent Phosphor Ceramics for High-Index Color Rendering and High-Power Lighting

Recent Advances in Preparing Transparent Phosphor Ceramics for High-Index Color Rendering and High-Power Lighting

Al₂O₃–Ce:YAG composite phosphor ceramics for white laser lighting: Novel preparation and regulatable properties

A single‐structured LuAG:Ce,Mn phosphor ceramics with high CRI for high‐power white LEDs

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Improving the CRI of Al2O3-YAG:Ce eutectic for high-power white LEDs applications: Energy-transfer and co-luminescence

Cited by 11 publications

References 35 publications

Recent Advances in Preparing Transparent Phosphor Ceramics for High-Index Color Rendering and High-Power Lighting

Recent Advances in Preparing Transparent Phosphor Ceramics for High-Index Color Rendering and High-Power Lighting

Al2O3–Ce:YAG composite phosphor ceramics for white laser lighting: Novel preparation and regulatable properties

A single‐structured LuAG:Ce,Mn phosphor ceramics with high CRI for high‐power white LEDs

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Al₂O₃–Ce:YAG composite phosphor ceramics for white laser lighting: Novel preparation and regulatable properties