The Fabrication And The Upconversion Luminescence Of NaYF₄:Yb³⁺,Er³⁺ With Inverse Opal Photonic Crystals

In recent years,because of resources^'overuse and the environment irreversibledestruction,the development of new energy,newresources,improve the utilization rate are imminent.Improving people's living standards,the pursuit of quality of life is more and more high,the paper developed a new adaptation of high-quality resources of human life is also necessary.Fabrication and the upconversion luminescence of NaYF₄:Yb³⁺,Er³⁺with inverse opal photonic crystals,it can get involved in information processing,medicine,solar cell,biological markers etc,it has good application prospects.Photonic crystal is a regular optical structure by periodic arrays of different refractive medium.Photonicband gap can block the specific frequency,the light can be modulated by the photonic band gap.Because of low phonon energy fluoride matrix,reduce nonradiative loss,so it has high conversion efficiency.Therefore,the upconversion luminescence properties of NaYF₄:Yb³⁺,Er³⁺with photonic crystal structure were investigated.we prepared rouhgly the same size of polystyrene microspheres by soap-free emulsion preparation.polystyrene microspheres were centrifuged,to obtain a symmetrical polystyrene microspheres,and then using the self-assembly method to make opal photonic crystal.The NaYF₄:Yb³⁺,Er³⁺is prepared by using sol-gel method,these templates were filled into sol solution.Then the opal templates can be removed by muffle furnace after calcined 1 hours to get the inversion structure of opal,which is called inverse opal photonic crystal?IOPC?.NaYF₄:Yb³⁺,Er³⁺inverse opal photonic crystal is formed.The luminescence properties of NaYF₄:Yb³⁺,Er³⁺inverse opal photonic crystals were analyzed.The experimental results show that the 510-530nm and 530-570nmgreen emission can be observe by photonic crystal structure NaYF₄:Yb³⁺,Er³⁺energy transfer?ET?,cross-relaxation process?CR?which is corresponding to the²H_11/2?⁴I_15/25/2 and ⁴S_15/2?⁴I_15/2;It is also can be observe that the 650nm-700nm red emissionby Yb³⁺,Er³⁺energy transfer,which iscorresponding to the⁴F_9/2?⁴I_15/2,the theoretical data also showed that the PBG could obvious inhibit the spontaneous emission when the PBG postion of erbium and ytterbium co-droped sodium yttrium fluoride completely overlaps the main emission band.