Preparation And Properties Of Rare Earth Ion Doped Yttrium Oxide Upconversion Luminescence Materials

The up-conversion luminescent material is an important rare earth luminescentmaterial. Up-conversion (UC) phosphors have been investigated extensively becauseof their potential application in various ifelds, such as upconversion lasers, medical,technology of anti-counterfeiting, three-dimensional display, communication,d3etection and so on. The upconversion material Y2O3： Yb+,E3r+is one of the mostpromising due to its high corrosion resistivity, thermal stability and low vibrationalrfequency and high eiffciency of the upconversion. Although certain progress hasbeen made in this area, the theoretical system on upconversion luminescent materialis not perfect. More studies are needed. For example, the mechanism for formingnanoparticles and research on surface modification need to be investigated in detail.In this project, E3r+Single-doped Y2O3： E3r+and Yb3+/E3r+co-doped Y2O3：Yb3+，E3r+were prepared by a simple hydrothermal method following by further heattreatment. Atfer that, effect of different Yb3+concentration, different E3r+concentration, different hydrothermal temperature and time and different annealingtemperature on the up-conversion luminescence of Y2O3： Yb3+,E3r+wereinvestigated in detail respectively and the optimal conditions for preparingup-conversion luminescence material with better performance was explored. Thelight-emitting mechanism of the up-conversion luminescence was further discussed.The samples have been characterized by X-ray difrfaction (XRD), field-emissionscanning electron microscopy (FESEM) and transmission electron microscopy(TEM). Under the980-nm exciter excitation, the transformation on the luminousperformance was studied. We can see that the annealing temperatures have positiveimpact on the enlargement of upconversion luminescence, and make a preliminaryanalysis of the reason; based on the research of the water thermal response time, think that the best time to hydrothermal synthesis is24hours.The effect of Yb3+concentration on the up-conversion luminescence of Y2O3：Yb3+3,Er+was investigated. Results showed that Yb3+increased the luminousintensity of upconversion luminescence when its amount was not too high. When theconcentration of Yb、+increases too much，it led to a decrease in intensity of3upconversion luminescence In detail, the function of Yb+is very small when theconcentration of Yb” is very low, because the excited-state absorption processoccurs under very small Yb)+concentration, then the energy transfer processbecomes weak. Therefore, even Yb3+can absorb photons of980nm under thissituation, it ’cant transfer the energy to E3r+. Yb3+could only works when its3concentration reaches a certain degree. The effect of Er+concentration on theup-conversion luminescence of Y2O3： Yb3+3,Er+was investigated. With the increase3of Er+concentration, the red emission intensity increase first，then decreases3remarkably. When the concentration of Er’ is low, the samples of the single3conversion mechanism is mainl+y used on the ESA process of Er, when dopedconcentration of Er+is higher, the sample on the transformation mechanism is theCET process, When the concent3ration of Er+is too high，concentration quenchingphenomenon happens.