青色及び青緑色蛍光体(Ba, Sr)MgAl_<10>O_<17> : Eu, Mnの発光特性とランプ特性

概要

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Various compositions of Ba_<1-α-β>Sr_αEu_βMg_<1-γ>Mn_γAl_<10>O_<17>(BAM)phosphors were prepared. Their emission spectra and the dependence of efficiency on temperature under 254nm excitation were studied. The more α and/or β values, the longer the emission wavelength of Eu^<2+> and the lower the efficiency at high temperature. A configurational coordinate model shows that these changes are due to a shortening of the Eu^<2+>-O^<2-> distance in the phosphor crystal. Furthermore, tricolor fluorescent lamps, which use one of these phosphors as the blue component, were simulated. It was calculated that, by increasing α or β from the conventional values of α=0, β=0.1 and γ=0.02, R_a can be increased without a reduction in luminous flux. The higher the color temperature of the lamp, the more its R_a and luminous flux depend on the composition of BAM. The maximum R_a achieved by changing the composition of BAM in each color temperature increases with an increase in the color temperature, while the luminous flux decreases. R_a=90 is predicted for a lamp in which the phosphor layer consists of a mixture of only three kinds of phosphors:BAM with α=0.3, β=0.1 and γ=0.015, Y_2O_3:Eu and LaPO_4:Ce, Tb. Two kinds of lamps were prepared and tested, and the simulation results were confirmed.
社団法人照明学会の論文
1998-08-01