Optical properties of Pb1 − xSnxSe quantum dots (QDs) in silicate glasses dictated by GeO2 concentrations

Effects of SnO addition on the optical properties of Pb1 − xSnxSe quantum dots (QDs) were investigated as a function of GeO2 content [GeO2] in germanosilicate glasses. Addition of SnO resulted in a red-shift of the absorption bands from QDs at [GeO2] < 20 mol%, but in a blue-shift at [GeO2] ≥ 20 mol%. Addition of GeO2 to the glass caused a large decrease in its viscosity, so it increased diffusion coefficient (D); as a result the amount of Sn in Pb1 − xSnxSe QDs increased. D of Sn2 + was ~ 560 times higher in the glasses with [GeO2] = 40 mol% than in the glass with no GeO2. The differences in Sn content in QDs affected their bandgap.