Achievement Of Color-adjustable Borate Phosphor And Its Property Based On Energy Transfer And Host Composition

A series of M₃Tb?BO₃?₃:Ln³⁺(M=Sr and Ba,Ln=Sm³⁺and Eu³⁺),Ca₂BO₃Cl:Eu²⁺,nM²⁺?M=Sr and Ba?and Ca₂?BO₃?_1-x?PO₄?_xCl:Eu²⁺phosphors were synthesized.The microstructure,X-ray diffraction,luminenscent properties,energy transfer,chromaticity coordinates and theremal properties of the phosphors were studied.?1?A series of new tunable emission phosphors of Sm³⁺and Eu³⁺single-doped M₃Tb?BO₃?₃?M=Sr and Ba?phosphors were synthesized by the solid-state reaction.crystallization behavior and structure,reflectance spectral properties,luminescence properties,energy transfer,lifetimes,temperature dependent luminescence properties and CIE chromaticity coordinate of M₃Tb?BO₃?₃:Ln³⁺?M=Sr and Ba,Ln=Sm and Eu?were systematically investigated.M₃Tb?BO₃?₃?M=Sr and Ba?crystallizes in a rhombohedral cell with space group R-3 by Rietveld structure refinement of the obtained phosphors with the standard data of Ba₃Dy?BO₃?₃.Sr₃Tb?BO₃?₃ and Ba₃Tb?BO₃?₃ emit yellowish-green emission with the main peak around 555 nm and 550 nm,respectively,which originates from ⁵D₄?⁷F₄ transition of Tb³⁺,and M₃Tb?BO₃?₃:Ln³⁺?Ln=Sm and Eu?phosphors show intense yellowish-green,yellow,orange and red emission with increasing Ln³⁺concentration under274 nm and 286nm excitation.The orange-red/red emissions peaked at 613nm(Sr₃Tb?BO₃?₃:Sm³⁺),627nm(Sr₃Tb?BO₃?₃:Eu³⁺),607nm(Ba₃Tb?BO₃?₃:Sm³⁺)and 625nm(Ba₃Tb?BO₃?₃:Eu³⁺)are contributed to the efficiently energy transfer Tb³⁺?Sm³⁺and Tb³⁺?Eu³⁺.?2?Single-phased and single Eu²⁺doped warm white-light phosphors Ca₂BO₃Cl:Eu²⁺,nM²⁺?M=Sr and Ba?were synthesized by controlling cations substitution systematically.The XRD,luminenscence properties and CIE chromaticity coordinate of Ca₂BO₃Cl:Eu²⁺,nM²⁺?M=Sr and Ba?phosphors were anylysized.Warm white light can be clearly generated by combining the blue emission?⁴10nm?and the yellow emission?577nm?.In our case,for warm white phosphors CBL:Eu²⁺,0.07Sr²⁺and CBL:Eu²⁺,0.01 Ba²⁺,the corresponding color coordinates?x,y?is?0.3890,0.3538?and?0.3602,0.3171?,CCT is 3647K and 3980K,and meanwhile Ra value is 64 and 80,separately.Therefore,a wider spectral distribution of blue and yellow emissions for CBL:Eu²⁺,M²⁺?M=Sr and Ba,?is sufficiently applied in high-quality white-lighting source for indoor lighting.The use of cations to replace the cations in the host to achieve a blue-yellow dual-emission single-doped phosphor is an effective method for the preparation of solid-state light sources.?3?High luminous efficacy,high-color-rendering index?CRI?,single-phased and single Eu²⁺doped warm white-light phosphors Ca₂?BO₃?_1-x?PO₄?_xCl were synthesized by controlling anion substitution systematically.The anionic polyhedron substitution of PO₄ for BO₃ causes a great distortion of the host lattice,which enables the tuning of luminescent properties.An additional distinct emission peaking at 462 nm(in addition to 577nm of Ca₂BO₃Cl:Eu²⁺)was observed under the same excitation when PO₄^3-was introduced.Therefore,with the crystal structure evolution,the ratio blue/yellow was changed by adjusting the ratio of BO₃/PO₄,which provides a new way for developing a high CRI warm white-light phosphor.The internal quantum efficiency?IQE?of the Ca₂?BO₃?_0.64?PO₄?_0.36Cl:Eu²⁺phosphor was 64.0%.Thewarmwhitelight-emittingdiode?w-LED?wasfabricatedwith Ca₂?BO₃?_0.64?PO₄?_0.36Cl:Eu²⁺phosphor and a 380 nm-emitting InGaN chip,which exhibited promising properties,such as the high Ra?83.4?,the low correlated color temperature?3907K?and high luminous efficacy?_L?30.4 lm/W?.Importantly,the w-LED shows a greater R9=39.3versus R9=14.3 of commercial YAG:Ce³⁺.As a warm white phosphor for Ca₂?BO₃?_1-x?PO₄?_xCl:Eu²⁺has a broad application prospect in indoor lighting.