Samarium doped apatite-type orange-red emitting phosphor Ca₅（PO₄）₂SiO₄ with satisfactory thermal properties for n-UV w-LEDs

Ze Zhang，Jialiang Niu，Wei Zhou，Dingdian Xu，Huanhuan Du

Department of Chemistry,School of Science,Beijing Technology and Business University

摘 要：A novel single-phase Sm³⁺ activated Ca₅（PO₄）₂SiO₄ phosphor was successfully fabricated via a conventional solid-state method, which can be e fficie ntly excited by near ultraviolet（n-UV） light-emitting chips.The crystal structure and luminescence properties were characterized and analyzed systematically by using relevant instruments. The Ca₅（PO₄）₂SiO₄:Sm³⁺ phosphor shows an orange-red emission peaking at600 nm under the excitation of 403 nm and the optimal doping concentration of Sm³⁺ is determined to be 0.08, The critical distance of Ca₅（PO₄）₂SiO₄:0.08 Sm³⁺ is calculated to be 1.849 nm and concentration quenching mechanism of the Sm³⁺ in Ca₅（PO₄）₂SiO₄ host is ascribed to energy transfer between nearestneighbor activators. The decay time of Ca₅（PO₄）₂ SiO₄: 0,08 Sm³⁺ is determined to be 1.1957 ms. In addition, the effect of temperature on the emission intensity was also studied, 72.4% of the initial intensity is still preserved at 250 ℃, better thermal stability compared to commercial phosphor YAG:Ce³⁺ indicates that Ca₅（PO₄）₂SiO₄:0.08 Sm3+ has excellent thermal stability and active energy is deduced to be 0.130 eV.All the results demonstrate that orange-red emitting Ca₅（PO₄）₂SiO₄:0.08 Sm³⁺ phosphor exhibits good luminescent properties. Owing to the excellent thermal quenching luminescence property,Ca₅（PO4）₂SiO₄:0.08 Sm³⁺ phosphor can be applied in n-UV white light emitting diodes and serve as the warm part of white light.

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