Composite phase ceramic phosphor of Al_2O_3-Ce:YAG for high efficiency light emitting

Tang, Yanru; Zhou, Shengming; Chen, Chong; Yi, Xuezhuan; Feng, Yue; Lin, Hui; Shuai, Zhang

doi:10.1364/oe.23.017923

Cited by 98 publications

(44 citation statements)

References 15 publications

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“…The Al 2 O 3 particle changes the propagation of the light in ceramic and break the total internal reflection (TIR) at the interface between ceramic and air, and that leads to the high extraction efficiency of light and high luminous efficacy of the Cr/Ce:YAG and Al 2 O 3 composite phase ceramic phosphor. 18 Therefore, the structure with composite phase is an effective approach for high luminous efficacy. Meanwhile, CRI was not improved as expected.…”

Section: Resultsmentioning

confidence: 99%

The Cr‐doping effect on white light emitting properties of Ce:YAG phosphor ceramics

Tang

Zhou

et al. 2017

J Am Ceram Soc

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The Cr/Ce‐doped YAG transparent ceramic was fabricated by the solid‐state reaction in vacuum. The Cr/Ce‐doped YAG ceramic phosphor effectively complement the red spectral component and improve the color rendering performance when excited by blue light that is due to the effective energy transfer between Cr3+ ion and Ce3+ ion. However, the energy transfer from Ce3+ to Cr3+ ion leads to energy loss and therefore the luminous efficacy of the WLED which is composed of blue LED chip and the Cr/Ce‐doped YAG ceramic phosphor decreases. The composite phase structure of ceramic phosphor is designed for improving the extraction efficacy and increasing the luminous efficacy by breaking the total internal reflection (TIR) at the interface between air and ceramic.

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Section: Resultsmentioning

confidence: 99%

The Cr‐doping effect on white light emitting properties of Ce:YAG phosphor ceramics

Tang

Zhou

et al. 2017

J Am Ceram Soc

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“…Recently, the YAG:Ce-Al 2 O 3 composite ceramic has been proposed for use in laser lighting because of its: i) high thermal conductivity and ii) high luminous efficacy caused by the scattering of secondary Al 2 O 3 grains. [17,24,28,30,33,37,[42][43][44] However, the refractive index difference between YAG (≈1.82) and Al 2 O 3 (≈1.76) is quite small, [45,46] even smaller than that between silicone (≈1.50) and YAG:Ce phosphor (≈1.82) which are widely used in white LEDs. Given that laser is a point light source with a much higher power density than LEDs, more efficient scattering centers are thus required to increase the light absorption and to homogenize the blue laser beam.…”

Section: Doi: 101002/lpor201900147mentioning

confidence: 99%

Unique Design Strategy for Laser‐Driven Color Converters Enabling Superhigh‐Luminance and High‐Directionality White Light

Zheng

Wei

et al. 2019

Laser & Photonics Reviews

113

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Robust ceramic color converters withstanding strong laser irradiations have recently drawn great attention for laser‐driven white lighting. However, the local emission within the incident laser spot usually expands to the whole surface area of the ceramics, which definitely makes it hard to achieve white light with high luminance and high directionality. Herein, a new strategy is proposed to solve the problem by elaborately introducing uniform spherical pores (diameter of ≈2 µm) into the phosphor ceramics with controlled contents from 8 to 24.6 vol%. The well‐distributed pores, acting as light scattering centers, enable reduction of the luminescent spot size greatly but without any losses in conversion efficiency. By using the high‐scattering ceramic color converters with 15% porosity, the light spot diameter is decreased by 46% and the central illuminance is increased by 156%. Moreover, laser‐driven white light with an enhanced beam directionality and uniformity is also achieved. A superhigh luminous flux of 7199 lm is realized by using this promising color converter in a rotary mode. The designed high‐scattering ceramics with controllable microstructures show great potential for use in extra‐high luminance laser‐driven lighting and projection.

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“…More recent color converter technologies use ceramics (Raukas et al, 2013) or glass-ceramics to overcome the problems of ageing and reliability (Bae et al, 2013). Table 1c shows principle technologies and material compositions of color conversion layers (Cangeloso, 2012;Chang et al, 2016;Dong et al, 2015;George et al, 2013;J€ ustel, 2013;Khanna, 2014;Li et al, 2016;McKittrick et al, 2013;McKittrick and Shea-Rohwer, 2014;Park et al, 2015;Patent, 2010;Tang et al, 2015;Wang et al, 2015;Ye et al, 2010;Yi et al, 2015). The purposes of filler particles like titanium dioxide are to increase the refractive index (Mont et al, 2008;Zheng et al, 2015) and the thermal conductivity of the entire matrix (Chung et al, 2012).…”

Section: Led Color Converter Materialsmentioning

confidence: 99%

Critical review on life cycle inventories and environmental assessments of LED-lamps

Franz

Wenzl

2017

Critical Reviews in Environmental Science and Technology

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Resource scarcity, hazardous waste, and climate change are the driving forces for developing energy efficient and low-toxic lighting sources. Currently, solid state lighting based on lightemitting diodes is expected to become the most dominant lighting technology of the future, mostly driven by its advantage with respect to energy efficiency. Parallel to the ongoing development of light-emitting diode-based lighting sources, a number of single case and comparative life cycle assessment studies of LED-lamps and components in varying study settings were carried out. However, these studies mostly rely to specific lamp designs, which limits general conclusions. This work includes a summary of the global market of lighting and LEDlamp technologies, followed by a comprehensive review and comparison of published life cycle assessment studies. In addition, we take also some aspects, which are relevant for the well-being of an end-user and which are usually not treated in life cycle assessment studies, like glare and health issues, into consideration. A critical interpretation of the assumptions and outcomes of these studies is given and questions that remain unsettled and therefore should be addressed in future studies are discussed.

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Composite phase ceramic phosphor of Al_2O_3-Ce:YAG for high efficiency light emitting

Cited by 98 publications

References 15 publications

The Cr‐doping effect on white light emitting properties of Ce:YAG phosphor ceramics

The Cr‐doping effect on white light emitting properties of Ce:YAG phosphor ceramics

Unique Design Strategy for Laser‐Driven Color Converters Enabling Superhigh‐Luminance and High‐Directionality White Light

Critical review on life cycle inventories and environmental assessments of LED-lamps

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