COMPLEX CALCIUM METASILICATE OF EUROPIUM AND YTTRIUM, RED LUMINESCENT MATERIAL BASED THEREON FOR ULTRAVIOLET LIGHT-EMITTING DIODES AND METHOD OF PRODUCING SAID MATERIAL Russian patent published in 2012 - IPC C09K11/79 C09K11/78 

FIELD: physics.

SUBSTANCE: red luminescent material contains an amorphised phase of silicon oxide SiO₂ and a crystalline phase dissolved therein, which contains microcrystals and is made of a complex calcium metasilicate of europium and yttrium Ca₃Eu_xY_2-x(SiO₃O₉)₂, where 1.0≤x≤1.5. To obtain luminescent material, two starting mixtures are prepared first: calcium carbonate and europium oxide; calcium carbonate and yttrium oxide, and said mixtures are dissolved in nitric acid while heating to 150-180°C. Tetraethoxy silane is added to the solutions which are cooled to room temperature and said solutions are then evaporated at 150-180°C to form dry residues. The dry residues are then calcined at 900-950°C for 10-12 hours, crushed, mixed and pelletised and then annealed at 1350-1400°C for 70-72 hours with double intermediate crushing, stirring and pelletisation. The obtained mixtures are mixed in ratio (1:1)-(1:3) in the presence of alcohol, briquetted and annealed at 1300-1350°C for 40-50 hours with intermediate stirring after 15-20 hours.

EFFECT: invention enables to convert ultraviolet radiation of a light-emitting diode with dominant wavelength in the range from 385 nm to 400 nm to the 567-714 nm band and provide volumetric luminescence.

3 cl, 3 dwg, 2 ex