A series of YNbO4∶Bi3+ and YNbO4∶Bi3+/Er3+ phosphors were prepared by a conventional high temper-ature solid-state reaction method.The results of XRD and Rietveld refinement confirm that monoclinic phase YNbO4 samples are achieved.The down-/up-conversion luminescence of Er3+ ions was investi-gated under the excitation of ultraviolet light (327 nm) and near infrared light (980 nm).Under 327 nm excitation,broad visible emission band from Bi3+ ions and characteristic green emission peaks from Er3+ions are simultaneously observed,while only strong green emissions from Er3+ ions are detected upon excitation of 980 nm.Remarkable emission enhancement is observed in down-/up-conversion lumi-nescence processes by introducing Bi3+ ions into Er3+-doped YNbO4 phosphors.Pumped current versus up-conversion emission intensity study shows that two-photon processes are responsible for both the green and the red up-conversion emissions of Er3+ ion.Through the study of the temperature sensing property of Er3+ ion,it is affirmed that the temperature sensitivity is sensitive to the doping concen-tration of Bi3+ ions.By comparing the experimental values of the radiative transition rate ratio of the two green emission levels of Er3+ ions and the theoretical values calculated by Judd-Ofelt (J-O) theory,it is concluded that the temperature sensing property of Er3+ ions is greatly affected by the energy level splitting.

Xin Wang;Xiangping Li;Hongquan Yu;Sai Xu;Jiashi Sun;Lihong Cheng;Xizhen Zhang;Jinsu Zhang;Yongze Cao;Baojiu Chen

School of Science,Dalian Maritime University,Dalian 116026,China

稀土学报（英文版）

[1]Xin Wang;Xiangping Li;Hongquan Yu;Sai Xu;Jiashi Sun;Lihong Cheng;Xizhen Zhang;Jinsu Zhang;Yongze Cao;Baojiu Chen-.Effects of Bi3+ on down-/up-conversion luminescence,temperature sensing and optical transition properties of Bi3+/Er3+ co-doped YNbO4 phosphors)[J].稀土学报（英文版）,2022(03):381-389

YNbO4

Effects,Bi3+,down,conversion,luminescence,temperature,sensing,optical,transition,properties,doped,phosphors,series,were,prepared,by,conventional,high,solid,state,reaction,method,results,Rietveld,refinement,confirm,that,monoclinic,phase,samples,achieved,was,investi,gated,under,excitation,ultraviolet,light,near,infrared,Under,broad,visible,band,from,characteristic,green,peaks,Er3+ions,simultaneously,observed,while,only,strong,emissions,detected,upon,Remarkable,enhancement,processes,introducing,into,Pumped,current,versus,intensity,study,shows,two,photon,responsible,both,Through,property,affirmed,sensitivity,sensitive,doping,concen,tration,By,comparing,experimental,values,radiative,rate,levels,theoretical,calculated,Judd,Ofelt,theory,concluded,greatly,affected,energy,splitting

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