Study of the Physicochemical and Spectral-Luminescent Characteristics of Materials Based on Quartz Glass and Yttrium–Aluminum Garnet Activated with Cerium

Compositions and a methodology for manufacturing composite materials for remote photoluminescent converters of LED radiation based on quartz glass and ultrafine powders of yttrium–aluminum garnet activated by cerium ions (Y₃Al₅O₁₂:Ce³⁺) are developed. The conditions for the synthesis of garnet by the method of thermochemical reactions (combustion) of nitrate salts in citric acid are optimized, and agglomerated powders with primary particle sizes of 0.8–12.3 μm are obtained for the reaction with a deficiency of acid and in the range from 49 to 207 nm for synthesis under conditions of excess citric acid. The physicochemical, structural, and spectral-luminescent characteristics of powdered samples and quartz glass–low-melting glass–phosphor composites formed at low sintering temperatures (650–700°C) are studied. It is shown that when the composite plate is illuminated with a blue LED (λ_max = 455 nm), a spot of white light is visually recorded, formed from a combination of scattered blue radiation and yellow radiation excited in YAG:Ce³⁺ particles (λ_max = 560 nm).