Preparation And Upconversion Luminescence Properties Study Of Yb³⁺/Ho³⁺/Tb³⁺ Co-doped Phosphate Glass

At present,most of the traditional lighting equipment on board ships uses halogen lamps with high power,which not only have a short service life,but also dissipate most of the energy in the form of heat,resulting in low luminous efficiency,which is contrary to the requirements of green economy.LEDs,due to their non-polluting,low energy consumption and fast response time,have received a lot of attention,making them a potential light source for marine lighting.A new phosphate（La₂O₃-P₂O₅）fluorescent glass doped with rare earth ions Yb³⁺,Ho³⁺and Tb³⁺was prepared by the conventional high temperature melting method to achieve white light emission from LEDs.Then,XRD diffractometer,ultraviolet-visible analyzer and fluorescence spectrometer were used to test the optical properties of fluorescent glass,and the influence of rare earth ion concentration on the fluorescence intensity and chromaticity coordinates of glass emission was analyzed,and finally how to carry out energy level transition and energy transfer between rare earth ions was discussed,and the concentration of rare earth ions in the sample when the white light emission effect is better was determined.The XRD pattern showed that the prepared fluorescent glass is amorphous and the UV-Vis absorption spectra indicated that Yb³⁺,Ho³⁺and Tb³⁺have good absorption in the band from 200nm to 1200nm,and combined with the excitation spectra and emission spectra of single doped Ho³⁺and Tb³⁺glasses,980nm was determined as the pumping source that was able to achieve co-emission of both ions.Under 980 nm excitation,Ho³⁺emission peaks were located at 545nm and 661nm,and Tb³⁺had a series of emission peaks in the 300nm-620nm band,and the maximum emission peak was located at 545nm,and the corresponding ion energy level jump was analyzed to calculate the chromaticity coordinates of the luminescent glass at different concentrations.Next,the ion concentrations in the Yb³⁺/Ho³⁺/Tb³⁺triple-doped glass were adjusted,and the energy transfer processes existed between Yb³⁺/Ho³⁺,Yb³⁺/Tb³⁺,and Tb³⁺/Ho³⁺ions,which were Yb³⁺→Ho³⁺,Yb³⁺→Tb³⁺,and Tb³⁺→Ho³⁺,respectively,were obtained by analyzing the changes in the intensity of the emission peaks,the energy transfer mechanism involved in the reduction of emission peak intensity was then discussed,and the fluorescence lifetime was tested,once again demonstrating that there is energy transfer between rare earth ionsFinally,the white light emission was achieved by adjusting the concentration ratio of rare earth ions,i.e.,the luminescence color of 2Yb³⁺/0.05Ho³⁺/0.4Tb³⁺triple-doped phosphate glass was close to white light.