Optical Multi-functional Design And Improvement Of Afterglow Properties Of Rare Earth Doped Luminescent Materials

Multifunction and high integration has always been a goal worth pursuing when important breakthroughs of multidisciplinary researches in the fields of thermo-luminescent,opto-electronic,photo-magnetic interaction,etc.,are emerged.Herein,we developed an all-purpose material with a tunable light emission property and controllable optoelectronic and optothermal response process.We showed a disappearance of emission behavior under the excitation of UV light by building a mid-gap host?Bi₂O₃?along with a rare earth(Sm³⁺)ion,with multiple energy level configurations,as an emission center.Thus,this phosphor is expected to open up the possibility of potentially free choice of light shielding,temperature sensing,and photodetection in a single-material system.Moreover,We also looked at ways to improve the performance of long afterglow.Focusing on the improvement of persistent duration,we used photoluminescence and thermally stimulated luminescence measurements to study the influence of different codopants M³⁺(M³⁺=Tm³⁺,Ga³⁺,Pr³⁺,Yb³⁺,Nd³⁺)on the luminescent quantum efficiency and traps distribution of Cr³⁺-doped stannate-baded long persistent phosphors(Zn₂SnO₄:Cr³⁺).And the results are as follows:?1?Bi₂O₃:Re³⁺(Re³⁺=Sm³⁺,Nd³⁺,Eu³⁺)phosphors were synthesized by high temperature solid state method for the first time.The results of X-ray diffraction show that all samples with different doping concentration have the same version of as pure Bi₂O₃,and there was no second phase.At the same time,the optimum doping concentration of doped ions was found according to the different doping gradient of the samples.Bi₂O₃ and Bi₂O₃:Sm³⁺band gaps have been obtained,through experimental tests and theoretical studies,and energy levels have been submerged,successfully.No emission behavior under the excitation of UV light?wavelength<450 nm?could be observed although distinct emission peak still existed.We also demonstrated the phenomena of temperature-induced population redistribution and temperature-induced spectral shift in the Bi₂O₃:Sm³⁺phosphor.Moreover,the Bi₂O₃:Re³⁺(Re³⁺=Sm³⁺,Nd³⁺,Eu³⁺)sample showed an excellent current response at different illumination wavelength and had an obvious change with the increasing intensity and wavelength of the excitation source.?2?We have successfully synthesized a NIR long persistent Zn₂SnO₄:0.3%Cr³⁺,0.5%M³⁺(M³⁺=Tm³⁺,Ga³⁺,Pr³⁺,Yb³⁺,Nd³⁺)via solid-state-reaction method.The results of X-ray diffraction show that all samples with different doping concentration have the same version of as pure Zn₂SnO₄,and there was no second phase.It featured an emission band from 650 to 850 nm,peaking at 810 nm.We used photoluminescence and thermally stimulated luminescence measurements to study the influence of different codopants(M³⁺=Tm³⁺,Ga³⁺,Pr³⁺,Yb³⁺,Nd³⁺)on the luminescent quantum efficiency and traps distribution.Finally,this work reveals that Tm³⁺is the most suitable codopant for enhancing the luminescent intensity and providing optimal trap depth for room temperature afterglow.