| Rare-earth doped luminescent materials have broad application foreground in solid-state lasers,bioluminescence probes,laser forgery and temperature sensors.However,the application of the upconversion luminescence?UCL?material was limited by low luminescence efficiency.So enhancing the luminescence of the material was of great significance.To solve this issue,following researches had been made.1.ScVO4:Ln3+ was synthesized by solid-state method,hydrothermal method and solvothermal method,and showed three different morphologies?spheroidicity,spindle-shape,chips-like shapes?.UCL of Yb3+/Er3+,Yb3+/Ho3+,Nd3+/Yb3+/Er3+,Nd3+/Yb3+/Ho3+ co-doped ScVO4:Ln3+ excited by 980 nm and 808 nm diode lasers was studied.All of the ScVO4:Yb3+/Er3+ samples exhibited strong emissions in the green region?near 525 and 550 nm?and weaker red emission,leading to green UCL on the whole.The UCL mechanism of ScVO4:Yb3+/Er3+ was investigated by Raman.2.Multi-ion co-doped ScVO4:Yb3+/Er3+ was synthesized by co-doped Li+,Na+,K+,Mg2+,Ca2+,Sr2+,Ba2+,and Gd3+,Y3+,Lu3+.The UCL of ScVO4:Yb3+/Er3+ was all enhanced by individually doped with Li+,Na+,K+.The UCL of ScVO4:Yb3+/Er3+ was enhanced by 6.24 times by doping 5% Li+.The UCL of ScVO4:Yb3+/Er3+ was enhanced by doping Ca2+ and Sr2+ and weaken by doping Mg2+ and Ba2+.The UCL of ScVO4:Yb3+/Er3+ was improved by 1.02 times by doping 1% Ca2+.The UCL of ScVO4:Yb3+/Er3+ were all enhanced by individually doped with Gd3+/Y3+/Lu3+.The UCL of ScVO4:Yb3+/Er3+ was greatly improved by doping 10% Lu3+.Adjust the doping amount of Gd3+?10%-100%?,the phase of GdVO4 appears when the doping amount of Gd3+ is 30%,the UCL of ScVO4:Yb3+/Er3+ was 1.71 times enhanced by doping by 30% Gd3+.When Li+/Ca2+?Li+/Gd3+,Ca2+/Gd3+?were co-doped in ScVO4:Yb3+/Er3+,the UCL of ScVO4:Yb3+/Er3+ co-doping Gd3+/Li+ and Gd3+/Ca2+were enhanced,and the UCL of ScVO4:Yb3+/Er3+ was enhanced by 2.23 times by co-doping Gd3+/Ca2+.The UCL of ScVO4:Yb3+/Er3+ was weakened by co-doping Ca2+/Li+.But Li+/Gd3+/Ca2+ co-doped ScVO4:Yb3+/Er3+ show weak UCL.3.The response of the UCL of ScVO4:Yb3+/Er3+ to temperature was studied.ScVO4:Yb3+/Er3+ was found to show good thermo-sensitivity.2H11/2 and 4S3/2 were thermal coupling level of Er3+.The ratio of peak intensity?524 nm / 554 nm?has a good linear relationship with temperature.The potential of ScVO4:Yb3+/Er3+applications in temperature sensors is possible.4.Li+,Ca2+ and Gd3+?Li+/Ca2+,Li+/Gd3+,Ca2+/Gd3+,Li+/Ca2+/Gd3+?co-doped LuPO4:Yb3+/Ho3+ and Lu PO4:Yb3+/Er3+ were synthesized by coprecipitation method.The UCL of them was all enhanced.The UCL of LuPO4:Yb3+/Ho3+ was enhanced by1.4 times by co-doping Gd3+/Li+.The UCL of Lu PO4:Yb3+/Er3+ was enhanced by 4times by co-doping Ca2+/Li+.Small range of color control of Lu PO4:Yb3+/Ho3+/Er3+samples were achieved by co-doping with Li+,Ca2+ and Gd3+?Li+/Ca2+,Li+/Gd3+,Ca2+/Gd3+,Li+/Ca2+/Gd3+?. |
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