Red phosphor materials play a key role in improving the lighting and backlit display quality of phosphor-converted white light-emitting diodes(pc-WLEDs).However,the development of a red phosphor with simultaneous high...Red phosphor materials play a key role in improving the lighting and backlit display quality of phosphor-converted white light-emitting diodes(pc-WLEDs).However,the development of a red phosphor with simultaneous high efficiency,excellent thermal stability and high colour purity is still a challenge.In this work,unique non-concentration quenching in solid-solution Cs_(3)Gd_(1-x)Ge_(3)O_(9):xEu^(3+)(CGGO:xEu^(3+))(x=0.1-1.0)phosphors is successfully developed to achieve a highly efficient red-emitting Cs_(3)EuGe_(3)0_(9)(CEGO)phosphor.Under the optimal 464 nm blue light excitation,CEGO shows a strong red emission at 611 nm with a high colour purity of 95.07%and a high internal quantum efficiency of 94%.Impressively,this red-emitting CEGO phosphor exhibits a better thermal stability at higher temperatures(175-250℃,>90%)than typical red K2SiF6:Mn^(4+)and Y203:Eu^(3+)phosphors,and has a remarkable volumetric negative thermal expansion(coefficient of thermal expansion,a=—5.06×10^(-5)/℃,25-250℃).By employing this red CEGO phosphor,a fabricated pc-WLED emits warm white light with colour coordinates(0.364,0.383),a high colour rendering index(CRI=89.7),and a low colour coordinate temperature(CCT=4508 K).These results indicate that this highly efficient red-emitting phosphor has great potential as a red component for pc-WLEDs,opening a new perspective for developing new phosphor materials.展开更多
基金supported by the National Natural Science Foundation of China(NSFC Nos.51932009,51929201,51672265,51672266,51750110511,51672257,52072349 and 51672259)Science and Technology Cooperation Project between Chinese and Australian Governments(2017YFE0132300)+1 种基金the Key Research Programme of Frontier Sciences,CAS(Grant No.YZDY-SSW-JSC018)Jiangmen Innovative Research Team Programme(2017)and Major Programme of Basic Research and Applied Research of Guangdong Province(2017KZDXM083).
文摘Red phosphor materials play a key role in improving the lighting and backlit display quality of phosphor-converted white light-emitting diodes(pc-WLEDs).However,the development of a red phosphor with simultaneous high efficiency,excellent thermal stability and high colour purity is still a challenge.In this work,unique non-concentration quenching in solid-solution Cs_(3)Gd_(1-x)Ge_(3)O_(9):xEu^(3+)(CGGO:xEu^(3+))(x=0.1-1.0)phosphors is successfully developed to achieve a highly efficient red-emitting Cs_(3)EuGe_(3)0_(9)(CEGO)phosphor.Under the optimal 464 nm blue light excitation,CEGO shows a strong red emission at 611 nm with a high colour purity of 95.07%and a high internal quantum efficiency of 94%.Impressively,this red-emitting CEGO phosphor exhibits a better thermal stability at higher temperatures(175-250℃,>90%)than typical red K2SiF6:Mn^(4+)and Y203:Eu^(3+)phosphors,and has a remarkable volumetric negative thermal expansion(coefficient of thermal expansion,a=—5.06×10^(-5)/℃,25-250℃).By employing this red CEGO phosphor,a fabricated pc-WLED emits warm white light with colour coordinates(0.364,0.383),a high colour rendering index(CRI=89.7),and a low colour coordinate temperature(CCT=4508 K).These results indicate that this highly efficient red-emitting phosphor has great potential as a red component for pc-WLEDs,opening a new perspective for developing new phosphor materials.
