Ultraviolet to near-infrared energy transfer in NaYF₄:Nd³⁺,Yb³⁺ crystals

董晓斌，由芳田，彭洪尚，黄世华

Key Laboratory of Luminescence and Optical Information,Ministry of Education,Institute of Optoelectronic Technology,Beijing Jiaotong University

摘 要：To convert ultraviolet（UV） light into near-infrared（NIR） light in phosphors is demanded for the development of solar cells.A series of NaYF₄:Nd³⁺,Yb³⁺ white powder samples were prepared via the hydrothermal method.The crystal structure and photoluminescence properties of the samples were carefully studied using X-ray diffractometry（XRD） and photoluminescence spectra.The excitation and emission spectra of NaYF₄:Nd³⁺,Yb³⁺ samples and the luminescence decay curves of Nd³⁺ and Yb³⁺ revealed an efficient energy transfer process from Nd³⁺ to Yb³⁺.This process resulted in the Yb³⁺ NIR fluorescent emission at 980 nm.Moreover,the lifetime of the Nd³⁺⁴F_3/2 level decreased with the increase of Yb³⁺ doping concentration.The build-up time of the decay curves of the Yb³⁺²F_5/2 level further verified the energy transfer process.Meanwhile,energy transfer efficiency based on different Yb³⁺ doping concentrations was achieved.

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