Mid-infrared luminescence from Sn-modified PbSe quantum dots in silicate glasses

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 Pb0.92Sn0.08Se 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.