Study On Preparation And Up-conversion Luminescent Of White-light Oxyfluoride Siclic-alumiumate Powder

In this work, we used solid state method to prepare a novel matrix:oxyfluoride siclic-aluminate white powers that exploiting additive synthesis of Red, Green, and Blue ones. All samples were excited by a single source of 980nm near-infrared radiation at room temperature to generate visible emissions through infrared--visible frequency up-conversion.In the Yb3+,Ho3+ codoped system, green(541nm) and red (648nm)luminescence signals were assigned to holmium ion 5S2(5F4)â†'5I8 and 5F5â†'5I8. In the Yb3+,Er3+ codoped system, green(521nm,540nm) and red(668nm) signals were assigned to erbium 4S3/2(2H11/2)â†'4I152,4F9/2â†'4I15/2 respectively. Also, in the Yb3+,Tm3+ codoped system, thulium ion 1G4â†'3H6 and 3F3â†'3H6 accordingly generate blue and red emission. The bule emission (480nm) was due to three photon process while others were two photon process. The concentrations of the rear-earth ions in the Yb3+,Er3+ codoped system were at a very high level.Laterly, based on the rare-earth concentrations of the above three primary color materials, we prepared triply-doped Yb3+, Tm3+, Ho 3+/Er3+ systems in order to generate white light by means of altering their doping concentrations. After studying the up-conversion luminescent process carefully, we noticed that the sensor was not only ytterbium ions but the thulium ions can sensitive the activators:Ho3+/Er3+ ions through corss relaxation. Fortunately, during the particular pump power range, the optimal one of Yb3+,Tm3+,Ho3+ system can locate in the white range in CIE1931 which chromaticity coordination was (x=0.337,y=0.338) which was close to the standard equal energy white light. Nevertheless, the triply-doped Yb+,Tm+,Er3+ system was not according to our anticipation. Its CIE1931 chromaticity coordinations fell into the green light range instead of white. As the pump power increase, both of their CIE1931 coordinates approaches to be much richer in blue. The discussion lay great stress on the energy transfer processes and up-conversion mechanisms.Additionally, the sample W1 was characterized by XRD, SEM and FT-IR. From those results, we conclude that sample W1 have achieved our expected targets partially and show its great potential in up-conversion light display.