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

FIELD: optical engineering.

SUBSTANCE: blue-emitting photoluminophor intended for indicator devices is depicted by formula Ba_1-xMgEu_xAl_10-y-zSc_yIn_zO₁₇, where x = 0.01-0.2, y = 0.05-0.3, and z = 0.01-0.25. Emission band of Eu²⁺ excited within wavelength range from 100 to 250 nm has spectral maximum at wavelength 450±5 nm, whose half-width rises with increased Eu²⁺concentration. Luminophor grains have oval-like rounded shape. Its great axis relates to wavelength of emitted light as 4:1 to 10:1. Average grain size is 2.8-3.0 mcm. Photoluminophor is prepared by first mixing hydroxides of elements composing photoluminophor taken in stoichiometric amounts and heated to 100^оС. Resulting mixture is pulverized with an inert gas to fine state and then calcined at 1350-1550^оС for 1 to 5 h in weakly reducing atmosphere. Thermally treated photoluminophor is coated with magnesium silicate film by allowing luminophor grains to react with composition containing Mg(OH)₂ and H₂SiO₃, whereupon grains are dried 1-3 h at 140^оС. Thus obtained photoluminophor has stable color coordinates x ≤ 0.155, y ≤ 0.06. It is hydrolytically stable, long-lasting, capable of incessantly working in gas panels and has high initial brightness.

EFFECT: improved performance characteristics.

3 cl, 1 tbl, 3 ex