Phosphor-converted white-light-emitting diodes(pc-WLED)have been extensively employed as solid-state lighting sources,which have a very important role in people’s daily lives.However,due to the scarcity of the red co...Phosphor-converted white-light-emitting diodes(pc-WLED)have been extensively employed as solid-state lighting sources,which have a very important role in people’s daily lives.However,due to the scarcity of the red component,it is difficult to realize warm white light efficiently.Hence,red-emitting phosphors are urgently required for improving the illumination quality.In this work,we develop a novel orangish-red La_(4)GeO_(8):Bi^(3+) phosphor,the emission peak of which is located at 600 nm under near-ultraviolet(n-UV)light excitation.The full width at half maximum(fwhm)is 103 nm,the internal quantum efficiency(IQE)exceeds 88%,and the external quantum efficiency(EQE)is 69%.According to Rietveld refinement analysis and density functional theory(DFT)calculations,Bi^(3+) ions randomly occupy all La sites in orthorhombic La_(4)GeO_(8).Importantly,the oxygen-vacancy-induced electronic localization around the Bi3+ions is the main reason for the highly efficient orangish-red luminescence.These results provide a new perspective and insight from the local electron structure for designing inorganic phosphor materials that realize the unique luminescence performance of Bi^(3+) ions.展开更多
基金supported by the National Natural Science Foundation of China(Grants Nos.51672259,51720105015,51672265,21521092,51750110511,and 21872174)Key Research Program of Frontier Sciences of CAS(YZDY-SSWJSC018)+8 种基金the CAS-Croucher Funding Scheme for Joint Laboratories(CAS18204)the Scientific and Technological Department of Jilin Province(Grant No.20170414003GH)Project of Innovation-Driven Plan in Central South University(2017CX003)State Key Laboratory of Powder Metallurgy in Central South UniversityThousand Youth Talents Plan of ChinaHundred Youth Talents Program of HunanShenzhen Science and Technology Innovation Project(630)Jiangmen Innovative Research Team Program(2017)Major program of basic research and applied research of Guangdong Province(2017KZDXM083).
文摘Phosphor-converted white-light-emitting diodes(pc-WLED)have been extensively employed as solid-state lighting sources,which have a very important role in people’s daily lives.However,due to the scarcity of the red component,it is difficult to realize warm white light efficiently.Hence,red-emitting phosphors are urgently required for improving the illumination quality.In this work,we develop a novel orangish-red La_(4)GeO_(8):Bi^(3+) phosphor,the emission peak of which is located at 600 nm under near-ultraviolet(n-UV)light excitation.The full width at half maximum(fwhm)is 103 nm,the internal quantum efficiency(IQE)exceeds 88%,and the external quantum efficiency(EQE)is 69%.According to Rietveld refinement analysis and density functional theory(DFT)calculations,Bi^(3+) ions randomly occupy all La sites in orthorhombic La_(4)GeO_(8).Importantly,the oxygen-vacancy-induced electronic localization around the Bi3+ions is the main reason for the highly efficient orangish-red luminescence.These results provide a new perspective and insight from the local electron structure for designing inorganic phosphor materials that realize the unique luminescence performance of Bi^(3+) ions.
