Study On The Preparation And Near-Infrared Luminescence Of Nd³⁺/Yb³⁺ Doped Phosphors

Recently, Nd³⁺/Yb³⁺ doped near infrared (NIR) luminescent materials have attracted significant attention due to their luminescent properties such as narrow emission spectra, long-live and large stokes shift. However, the NIR luminescence of Nd³⁺/Yb³⁺ doped materials is weak, which is the difficulty for their application. In this paper, we contribute to improve the NIR luminescence by using proper activators and hosts. The activators and hosts can improve the NIR luminescence performance by transferring energy to Nd³⁺/Yb³⁺. The conclusions and results were summarized as follows:Li2MSi04:Eu²⁺,Nd³⁺ (M=Ca, Sr, Ba) samples were prepared by high temperature solid method. It was found that Eu²⁺ can sensitize the NIR luminescence of Nd³⁺. The effect of Eu2-/Nd³⁺ concentration on luminescence properties was investigated. The intensity of the NIR luminescence reached maximum when the concentration of Eu²⁺ and Nd³⁺ are 1% and 7% in Li2CaSi04,1% and 5% in Li2SrSiO4,2% and 3% in Li2BaSi04. In Li2SrSi04, the energy transfer efficiency between Eu²⁺ and Nd³⁺ is much higher than those of the other two. This phenomenon can be expressed by the difference of Eu²⁺ emission in difference hosts.NIR luminescence material Na2Ca4(PO4)2SiO4:Ce³⁺,Tb³⁺,Yb³⁺ was synthesized by high temperature solid state method. The result showed that the doping of Ce³⁺ can improve the NIR luminescence through enhancing the intensity of Tb³⁺ luminescence. The phosphor which sintered at 1200℃for 1.5h and doped with 4%Ce³⁺,10%Tb³⁺ and 10%Yb³⁺ give the strongest NIR luminescence intensity. The Na2Ca4(PO4)2SiO4:Ce³⁺,Nd³⁺ phosphor was also prepared. It was found that the doping of Ce³⁺ can improve the NIR luminescence of Nd³⁺. The intensity of the NIR luminescence reached maximum when the concentration of Nd³⁺was 12%.ZnB2O4:Eu³⁺,Yb³⁺ and ZnMoO4:Eu³⁺,Yb³⁺ powders were synthesized by a solid state method. The different effect of the doping of Eu³⁺ was investigated. The energy transfer mechanism between ZnMoO4 host and Yb³⁺ was also discussed.NIR luminescence materials Gd2MoO6:Yb³⁺/Nd³⁺ were prepared by high temperature solid state method. It was found that the NIR luminescence performance of Gd2MoO6:Yb³⁺ is better than that of ZnMoO4:Yb³⁺. The effect of the prepared conditions and the doping of Bi³⁺ and W6+ on the NIR luminescence of samples were also investigated. The energy transfer mechanism between Bi³⁺ and Yb³⁺ was simply discussed.