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Infrared photoluminescence (PL) properties of Sn-modified PbSe quantum dots (QDs) in silicate glass were investigated. The QDs' sizes were controlled by changing the heat treatment temperatures. The longest absorption peak from Sn-modified PbSe QDs was centered at 2590 nm, and the PL band extended to 2650 nm. X-ray diffraction peaks indicated that the PbSe QDs formed in the glass matrix although low Sn content resulted in no obvious difference between PbSe QDs and Sn-modified PbSe QDs. Sn was found in QDs that proves the incorporation of Sn into PbSe QDs. The proposed composition of the Sn-modified PbSe QDs was Pb 0.92 Sn 0.08 Se with a band gap of ~ 0.13 eV; the small amount of Sn changed the energy structure of QDs, narrowed the band-gap, and increased the PL emission wavelength. [ABSTRACT FROM AUTHOR]

• Ternary Pb 1−x Sr x Se quantum dots were prepared in the silicate glass. • Pb2+ concentration determine the density of Pb 1−x Sr x Se QDs in glassy matrix. • The higher Se/Pb ratio facilitates the formation of large-size quantum dots. Lead selenide quantum dots (QDs) were precipitated in silicate glasses with different contents of SrO. As the concentration of SrO increased from 0 to 10 mol%, the absorption peaks of the glasses with the heat treatment at 520 °C for 10 h blue-shifted from 1535 nm to 947 nm, and their photoluminescence (PL) peaks from 1578 nm to 1184 nm. The blue-shifts resulted from the incorporation of Sr2+ ions into PbSe crystal lattice, which leads to the increase of the bandgap of PbSe QDs. Meanwhile, the optical properties of Sr2+-doped PbSe QDs were investigated by changing the precursor concentrations of Pb and Se. It is found that the concentration of Sr2+-doped PbSe QDs in the glassy matrix is mainly determined by the contents of the Pb precursor. To form larger size QDs requires higher oversaturation of Se to Pb elements, which promoted the further growth of QDs. [ABSTRACT FROM AUTHOR]