RED-EMITTING PHOTOLUMINOPHOR FOR GAS PANEL SCREENS AND A METHOD FOR PREPARATION THEREOF Russian patent published in 2004 - IPC

FIELD: optical engineering.

SUBSTANCE: red-emitting photoluminophor intended for indicator devices is depicted by formula: (Y_x,Gd_y,Eu_z,Ln_p)B_1-qMe+3q

O₃, where Ln is Yb and Se, Me⁺³ is Al and Ga, 0.5 ≤ x ≤ 0.38, 0.22 ≤ y ≤ 0.38, 0.01 ≤ z ≤ 0.10, 0.02 ≤ p ≤ 0.05, 0.02 ≤ q ≤ 0.10. This photoluminophor is efficiently excited in vacuum UV region. Ratio of principal emission lines corresponding to wavelengths 592 and 628 nm varies between 1:1 and 1:2 Grains of luminophor has oval shape and its geometric axis relates to wavelength of emitted light as 4:1 to 10:1. Average grain size ranges from 2.5 and 6 mcm. Grains form a tight packing with loose density ρ = 1,8 g/cm³ and dense luminescent layer emitting in transmission mode at specific load on screen δ = 2.0 to 4.1 mg/cm². Photoluminophor is prepared by mixing required stoichiometric amounts of corresponding nitrate crystal hydrates. Resulting mixture is heated to 80-100^оС and sodium tetrahydroborate, as precipitation agent, is added at 60^оС and vigorous stirring to form fine precipitate. The latter is thoroughly washed on nutsch filter with HCl solution. Washed product is calcined at 700-900^оС for 1-3 h and then at 1100-1300^оС for 0.5-3 h. Thus obtained photoluminophor shows saturated red color with high brightness when excited in vacuum UV region and has reduced afterglow duration.

EFFECT: increased resistance to high temperatures and corrosive media during manufacture of gas panel screens.

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