Preparation And Property Research Of Gallate Near-infrared Long Afterglow Luminescence Materials

The near infrared long persistence nano-phosphors materials have a ultra-long luminous life,make it can realize “no need for in situ excitation”,thereby,it can avoid tissue auto fluorescence,background interference and the phototoxic of biological tissue.Meanwhile,its emission wavelength locate at “biological optics window”,make it have a deep tissue penetration.Hence The research and development new type near-infrared long persistence molecular probes has extensive application prospect at biomedical imaging,diagnosis and therapy.But,nowadays,the development of optical imaging is at a bottleneck,the reason is the development of fluorescent probes can not keep up with the development of imaging equipment and imaging technology.The modern medical optical detection has the following several points:?1?The working window of fluorescent probe locate at biomedical window?700nm-1000 nm and 1100nm-1350nm?,in order to increase the deep tissue transmittance of the detection of light;?2?The excitation light of fluorescent probe should not apply ultraviolet and visible light,to avoid the auto fluorescent of the organization;?3?The exciting light intensity of fluorescence probe should not be too strong,so as to reduce the background signals,increase the imaging signal-to-noise ratio;?4?It can provide observation results real-time,entirety and distributive.Make a general survey of all potential fluorescent probe,only the near-infrared long afterglow luminescence materials can meet all the above requirements very well.But the earlier long afterglow luminescence materials is concentrated in the visible region,near-infrared long afterglow luminescence materials is very rare.This paper firstly made a system state of the history,theory model and methods to improve the afterglow performance of the materials.Then,through the explore and analyze of the long afterglow luminescence materials has been reported,develop the methods to improve the performance of near-infrared long afterglow luminescence materials by improve the anti-site defects concentrations,create new long afterglow trap and phase doping.Then,prepare the Cr³⁺,Er³⁺dual doping gallium acid to improve the luminescence property by improve the energy transfer efficiency.Specific research contents and results included as following aspects:?1?Prepare the ZnGa₂O₄:Cr³⁺luminescent materials by high temperature solid state method.And carried on the deep discussion of the synthesis of temperature,reaction time and chromium ion doping concentration of the material.Prepare the gallium luminescent material at different preparation temperature?1200?,1300?,1350?,1400?,1450?,1500??,different reaction time?3h,4h,5h,6h,7h?and different doping concentration?0.5%,0.75%,1.0%,1.25%,1.5%?.Determine the optimal synthesis temperature is 1450?,the optimal synthesis time is 5h,quenching concentration of chromium ion is1%.Then,on this base,we studied the emission spectrum and afterglow properties at different excitation wavelength excite.?2?Based on the meaning of chromium doped zinc gallate long afterglow luminescence materials is not enough to meet the requirements of modern medical optical detection,owing to its low afterglow intensity and time caused by its low defect concentration.The ZnGa_2-xSn_xO_4+x:Cr³⁺ luminescent material was prepared by high temperature solid state method,through introduced Sn⁴⁺ ion defects into octahedral space of zinc gallate,then formed V_Sn⁴⁺-Cr³⁺-VO^2-defect cluster to improve the performance of long afterglow luminescence of this material.And found that when the doping concentration in this material caused Zn₂SnO₄ and SnO₂ phase occurs,the improvement of long afterglow luminescence material is obvious at 400 nm excitation light,but at 300 nm excitation light,there are some degradation of the long afterglow luminescence performance.?3?Prepare the materials by doping Zn₂SnO₄ and SnO₂ phase respectively,Zn₂SnO₄ is the key point of the improvement of the long afterglow luminescence performance at 400 nm excitation light.And that,the doped SnO₂ phase make the materials quenching,result in the degradation of the long afterglow luminescence performance.And discuss the optimal concentration of Zn₂SnO₄ doping.?4?By introducing other luminescence center Er³⁺ ion at Cr³⁺ doped Zinc gallate,Er³⁺ ion and Cr³⁺ ion form co-doped ion pairs with energy transfer,to improve the long afterglow luminescence intensity and time.And discuss the optimal doping concentration of Er³⁺.Then,we doping Er³⁺ ion and Cr³⁺ ion at Zn₂SnO₄ doped zinc gallate to obtain the most optimal near-infrared long afterglow luminescence material.