Research On The Regulation Of Optical Signal,Magnetic And Thermal Effects For Upconversion Sensor

Lanthanide doped upconversion sensors have attracted much attention in recent years due to their unique optical properties,such as sharp emission peaks,low self-fluorescence background signals,long emission attenuation time,strong anti-photobleaching and light scintillation ability,and the ability to combine two or more photons into higher energy photons.However,the application of simple upconversion sensor is limited,and it can only adjust the optical signal.In order to break this restriction,people began to study the multi-function of the upconversion sensor.The multifunction of upconversion sensor makes it significant that upconversion sensor can adjust other physical quantities besides optical signal.In order to explore the above problems,this paper takes upconversion sensor as the research object,and fabricates different multi-functional upconversion sensor,and characterizes and analyses these multi-functional upconversion sensor.The main research work of this paper includes:?1?Although the main purpose of multifunctional upconverter is to expand the application scope of upconverter sensor,the control of optical signal is still the research focus of upconverter sensor.In this paper,a multi-functional upconversion sensor with uniform size and high luminescence efficiency was prepared by hydrothermal method.By adjusting the optical signals of rare earth ions and different ion doping concentration,the red,green and purple light signals with different intensities can be emitted under the excitation of 980 nm near infrared light.?2?A photomagnetic dual-function upconversion sensor has been successfully fabricated by doping different concentrations of ytterbium ion(Yb³⁺)and erbium ion(Er³⁺)to make the sensor have both upconversion luminescence and magnetic effect.Under the excitation of 980 nm infrared light,these photomagnetic bifunctional sensors emit about 540 nm green light from ⁴S_3/2-⁴I_15/2,657 nm red light from⁴F_9/2-⁴I_15/2 and 407 nm violet light from ²H_9/2-⁴I_15/2.In addition,the doped Yb³⁺concentration has a greater influence on the red emission.By increasing the doping concentration of Yb³⁺ions,the ratio of red light emission intensity to green light emission intensity can be significantly increased.At the same time,with the increase of Yb³⁺ion concentration,the paramagnetic properties are greatly improved.?3?A photothermal dual-function upconversion sensor has been successfully fabricated by doping lanthanum ions(La³⁺)with different concentrations to make the sensor have both upconversion luminescence and thermal effect.The photothermal bifunctional sensor can emit 520 and 540 nm green light signal,655 nm red light signal and 407 nm purple light signal.The results show that the photothermal efficiency of the photothermal upconversion sensor without La³⁺ion is much lower than that of the photothermal upconversion sensor with La³⁺ion.With the increase of doped La³⁺ion concentration,the photothermal efficiency of the photothermal upconversion sensor increases monotonously.Importantly,the time-resolved temperature curve shows that doping La³⁺ions can significantly increase the temperature rise rate of the photothermal upconversion sensor.This phenomenon of increasing the heating rate with the increase of La³⁺doping ion content is conducive to the application of photothermal effects,such as photothermal therapy,because the therapy can be completed in a relatively short time.In general,photomagnetic upconversion sensors and photothermal upconversion sensors were prepared by hydrothermal method,and the optical signals,magnetic properties and thermal effects of these upconversion sensors were regulated,which effectively reflected the performance of these upconversion sensors.