Новые апконверсионные объемные и нанолюминофоры на основе Sr-=SUB=-2-=/SUB=-Y-=SUB=-8-x-y-=/SUB=-Yb-=SUB=-y-=/SUB=-Tm-=SUB=-x-=/SUB=-Si-=SUB=-6-=/SUB=-O-=SUB=-26-=/SUB=-

Abstract

Polycrystalline phosphors with a Sr2Y8-x-yYbyTmxSi6O26 (x=0.005-0.5, y=0.2,0.3) total formula were synthesized. Nanoluminophor has been obtained from the Sr2Y7.695Yb0.3Tm0.005Si6O26 microcrystalline sample by the vacuum electron been evaporation, in the amorphous state, with the ~10.6 nm particle size. It is found, raman spectra undergoing modification by the transition from bulk- to nanosize state. Photoluminescene spectra micro- and nanophosphors are studied. Intensity of the blue emission, by the UV ligth excitation, grows in the x=0.005-0.02 region, with the x increasing. Upconversion photoluminescence (UPCL) spectra of the bulk phosphors and nanosample based on the Sr2Y7.695Yb0.3Tm0.005Si6O26 were measurd. At the pumping power around 70.8 mW, by the laser source with the λ=980 nm, thereshold population of the 3F3 level of Tm3+ ions exist. At a power higher 70.8 mW, a sharp increase of the luminescence intensityof the bulk- and nanophosphor occurs. For the 3H4->3H6 transition thereshold pumping power absent. This indicates that, pumping, during Yb->Tm energy transer, is a single photon process.