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

Abstract 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 (H 3 PO 3 ), dimethyldichlorosilane (Me 2 SiCl 2 ) and tin(II) chloride (SnCl 2 ) 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 4f 6 5d 1 → 4f 7 transition of Eu 2+ ions, whereas the fluorescence due to the 5 D 0 → 7 F j ( j =0, 1, 2) transitions of Eu 3+ ions was not observed. Owing to the redox reaction P 3+ + 2Eu 3+ → P 5+ + 2Eu 2+ , almost all of Eu 3+ ions incorporated into the glasses are considered to be reduced to Eu 2+ ions at a temperature as low as 250 °C.