Organic–inorganic hybrid phosphite low-melting glasses for photonic applications

Organic–inorganic hybrid low-melting phosphite glasses have been prepared through non-aqueous acid–base reactions of Si–Cl + P–OH → Si–O–P + HCl↑ and Sn–Cl + P–OH → Sn–O–P + HCl↑ using phosphonic acid (H3PO3), dimethyldichlorosilane (Me2SiCl2) and tin(II) chloride (SnCl2) as starting materials. Transparent, colorless and homogeneous phosphite glasses were successfully obtained. Organic molecules and Eu-codoped hybrid phosphite glasses were also prepared. The europium-doped glasses obtained at 250 °C showed a fluorescence with a broad peak at 373 nm due to the 4f65d1 → 4f7 transition of Eu2+ ions, whereas the fluorescence due to the 5D0 → 7Fj (<f>j=0</f>, 1, 2) transitions of Eu3+ ions was not observed. Owing to the redox reaction P3+ + 2Eu3+ → P5+ + 2Eu2+, almost all of Eu3+ ions incorporated into the glasses are considered to be reduced to Eu2+ ions at a temperature as low as 250 °C. [Copyright &y& Elsevier]