RED PHOSPHOR FOR COMPOSITE WHITE LIGHT LEDS BASED ON FLUORIDE BORATE POLYCRYSTALS AND METHOD FOR ITS PREPARATION Russian patent published in 2023 - IPC C09K11/55 C09K11/63 C09K11/86 C30B28/02 C30B29/10 F21V9/30 F21Y115/10 

FIELD: chemical industry; lighting engineering.

SUBSTANCE: used in the manufacture of composite white light LEDs, consisting of a chip emitting in the near ultraviolet and three phosphors: red, green and blue. To obtain a phosphor based on polycrystals of doped Eu³⁺ fluoride borate with the general formula LiBa₁₂(BO₃)₇F₄, a mixture of BaCO₃, BaF₂, Li₂CO₃, HBO₂, taken in stoichiometric proportions, and Eu₂O₃ is added in such an amount as to ensure a Eu content of 0.5-2.0 wt.% in the composition of the final product. Then solid-phase synthesis is carried out by three-stage annealing of the resulting mixture in air in the temperature range of 465-825°C, while the duration of the first stage, carried out in the temperature range of 465-500°C, at least 0.5 hours, and two subsequent ones, carried out at 700-750°C and 815-825°C, respectively, for at least 48 hours. The resulting phosphor is characterized by the above chemical formula and isomorphic replacement of barium ions with trivalent europium ions.

EFFECT: when excited in the near ultraviolet region at a wavelength of 395 nm, a red glow with a quantum yield of 60-63% and photoluminescence with CIE chromaticity coordinates and correlated color temperature (0.630; 0.374), 1947 K - (0.647; 0.374), 2072 K are provided.

3 cl, 3 dwg, 1 tbl, 3 ex