Solvothermal synthesis of red and green emitting Ca_(1.65)Sr_(0.35)SiO_4:Eu~(3+) and Ca_(1.65)Sr_(0.35)SiO_4:Eu~(2+) phosphors for solid-state lighting applications

摘要

A novel and facile synthetic approach has been trialed, and attempted with success in the preparation of two phosphors namely, a red emitting CaSrSiO_4:Eu~(3+) and a green emitting CaSrSiO_4:Eu~(2+). These phosphors were successfully synthesized using a simple co-precipitating solvothermal strategy wherein tetraethyl orthosilicatc (TEOS) as silica source and the acetate precursors of strontium (Sr~(2+)), calcium (Ca~(2+)) and europium (Eu~(3+)) are utilized. The material so obtained is subjected to an extensive photoluminescencc behavior study. The concentration of the dopant (Eu~(3+)and Eu~(2+)) plays a significant role in the determination of photoluminescence behavior and hence a systematic and in-depth experimental studies were done and the results are synchronized. On interpretation of the output, it came to light that an intense emission signals sparked in the red region (590 and 615 nm) in the case of phosphor doped with Eu~(3+), which is excited under near ultra violet (395 nm) and blue (466 nm) region. In case of the CaSrSiO_4 sample doped with Eu~(2+) an intense broad green signal (-510 nm) is obtained under the excitation range of 350-430 nm. The results obtained are quite encouraging and made a strong confirmation as, the solvo-thcrmally synthesized CaSrSiO_4, which is activated by the dopants namely Eu~(3+) and Eu~(2+) possesses an immense potential and it is exactly tapped by the adopted methodology. Despite its strong impact, it will also assure a strong revolution in the fabrication and thus the commercialization of white LEDs as both the red and green emitting phosphor.