A three-layered phosphor structure was designed and prepared by the spin coating of BaSi_(2)N_(2)O_(2):Eu(cyan-emitting)and(Sr,Ca)AlSiN_(3):Eu(red-emitting)phosphor films on the yellowemitting Y_(3)Al_(5)O_(12):Ce(YAG...A three-layered phosphor structure was designed and prepared by the spin coating of BaSi_(2)N_(2)O_(2):Eu(cyan-emitting)and(Sr,Ca)AlSiN_(3):Eu(red-emitting)phosphor films on the yellowemitting Y_(3)Al_(5)O_(12):Ce(YAG:Ce)phosphor ceramic synthesized by the solid-state reaction under vacuum sintering.In order to achieve high color rendering lighting,the influence of the composition and structure of the three-layered phosphors on the optical,thermal,and electrical properties of the chip-on-board(COB)packaged white-light-emitting diodes(WLEDs)was studied systematically.The WLED with the structure of“red+cyan+yellow”(R+C+Y)three-layered phosphor generated neutral white light and had a luminous efficacy of 75 lm/W,the fidelity index(R_(f))of 93,the gamut index(R_(g))of 97,and the correlated color temperature(CCT)of 3852 K.Under the excitation of laser diode(LD),the layer-structured phosphor yielded the white light with a luminous efficacy of 120 lm/W,color rendering index(CRI)of 90,and CCT of 5988 K.The result indicates that the three-layered phosphor structure is a promising candidate to achieve high color rendering and high luminous efficacy lighting.展开更多
The major advantage of laser lighting over white light-emitting-diode is the possibility to achieve ultra-high luminance.However,phosphors usually suffer laser-induced luminescence saturation,which limits the peak lum...The major advantage of laser lighting over white light-emitting-diode is the possibility to achieve ultra-high luminance.However,phosphors usually suffer laser-induced luminescence saturation,which limits the peak luminance of laser lighting devices.The aim of the present study is to develop LuAG:Ce/Al_(2)O_(3)composite ceramics(LACCs)with a high saturation threshold for high-luminance laser lighting.Owning to the rigid crystal structure,proper synthetic process,and optimized thermal design,the LACCs possess small thermal quenching(16%loss in luminescence at 225℃),high quantum yield(>95%),and excellent luminescence properties.When the LACCs are irradiated by blue laser diodes in a reflection mode,a high luminous flux of 4634 lm and luminous efficacy of 283 lm·W^(−1)are realized.Furthermore,they show no sign of luminescence saturation even when the power density reaches 20.5 W·mm^(−2).With these favorable properties,the designed LACCs show great potential in high-luminance laser lighting.展开更多
Today, energy saving and emission reduction are two big global issues. Power artificial lighting currently accounts for about 20% of the total global electricity consumption [1]. Solid-state lighting based on light-em...Today, energy saving and emission reduction are two big global issues. Power artificial lighting currently accounts for about 20% of the total global electricity consumption [1]. Solid-state lighting based on light-emitting diodes (LEDs) is bringing about a revolution in energy-efficient lighting, and the lighting industry is transformed into a rapidly growing business sector [2,3]. The solid-state lighting technology is basically based on phosphor- converted white LEDs (pc-LEDs), which are commonly fabricated by using the combination of InGaN blue-emitting LED chips and luminescent materials as color converters [4,5], Luminescent materials play a critical role in fabricating high-performance LED devices, which is strongly linked to LED's luminous efficacy, stability, color rendering index (CRI), correlated color temperature (CCT) and operation lifetime [6-8]. Therefore, the discovery of more efficient desirable phosphor materials is essential.展开更多
基金supported by the National Key R&D Program of China(Grant No.2017YFB0310500)the National Natural Science Foundation of China(Grant No.61775226)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA22010301)the key research project of the frontier science of the Chinese Academy of Sciences(No.QYZDB-SSW-JSC022).
文摘A three-layered phosphor structure was designed and prepared by the spin coating of BaSi_(2)N_(2)O_(2):Eu(cyan-emitting)and(Sr,Ca)AlSiN_(3):Eu(red-emitting)phosphor films on the yellowemitting Y_(3)Al_(5)O_(12):Ce(YAG:Ce)phosphor ceramic synthesized by the solid-state reaction under vacuum sintering.In order to achieve high color rendering lighting,the influence of the composition and structure of the three-layered phosphors on the optical,thermal,and electrical properties of the chip-on-board(COB)packaged white-light-emitting diodes(WLEDs)was studied systematically.The WLED with the structure of“red+cyan+yellow”(R+C+Y)three-layered phosphor generated neutral white light and had a luminous efficacy of 75 lm/W,the fidelity index(R_(f))of 93,the gamut index(R_(g))of 97,and the correlated color temperature(CCT)of 3852 K.Under the excitation of laser diode(LD),the layer-structured phosphor yielded the white light with a luminous efficacy of 120 lm/W,color rendering index(CRI)of 90,and CCT of 5988 K.The result indicates that the three-layered phosphor structure is a promising candidate to achieve high color rendering and high luminous efficacy lighting.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA22010301)the key research project of the frontier science of the Chinese Academy of Sciences(Grant No.QYZDB-SSW-JSC022).
文摘The major advantage of laser lighting over white light-emitting-diode is the possibility to achieve ultra-high luminance.However,phosphors usually suffer laser-induced luminescence saturation,which limits the peak luminance of laser lighting devices.The aim of the present study is to develop LuAG:Ce/Al_(2)O_(3)composite ceramics(LACCs)with a high saturation threshold for high-luminance laser lighting.Owning to the rigid crystal structure,proper synthetic process,and optimized thermal design,the LACCs possess small thermal quenching(16%loss in luminescence at 225℃),high quantum yield(>95%),and excellent luminescence properties.When the LACCs are irradiated by blue laser diodes in a reflection mode,a high luminous flux of 4634 lm and luminous efficacy of 283 lm·W^(−1)are realized.Furthermore,they show no sign of luminescence saturation even when the power density reaches 20.5 W·mm^(−2).With these favorable properties,the designed LACCs show great potential in high-luminance laser lighting.
文摘Today, energy saving and emission reduction are two big global issues. Power artificial lighting currently accounts for about 20% of the total global electricity consumption [1]. Solid-state lighting based on light-emitting diodes (LEDs) is bringing about a revolution in energy-efficient lighting, and the lighting industry is transformed into a rapidly growing business sector [2,3]. The solid-state lighting technology is basically based on phosphor- converted white LEDs (pc-LEDs), which are commonly fabricated by using the combination of InGaN blue-emitting LED chips and luminescent materials as color converters [4,5], Luminescent materials play a critical role in fabricating high-performance LED devices, which is strongly linked to LED's luminous efficacy, stability, color rendering index (CRI), correlated color temperature (CCT) and operation lifetime [6-8]. Therefore, the discovery of more efficient desirable phosphor materials is essential.
