Growth of lead selenide quantum dots in silicate glasses

Glass with the composition of 50SiO2-25Na2O-10ZnO-10BaO-5Al2O3 (in mol%) was used as the matrix for the growth of PbSe QDs. The viscosity-temperature relations of the glass were obtained through Vogel-Tammann-Fulcher equation. PbSe QDs were precipitated in this silicate glasses with the heat-treatment temperatures (TH) ranging from 490 to 540 °C for fixed duration of 10 h, corresponding to the glass-viscosity 1011.2-108.9 Pa·s. Meanwhile, the absorption peaks from PbSe QDs shifted from 872 nm to 2134 nm, and the PL peaks shifted from 1104 nm to 2185 nm. To study the PbSe QDs growth kinetics, the glasses were heat treated at 500, 520 and 540 °C for 1-20 h. Changes in diameter of PbSe QDs exhibited strong time dependencies (i.e. D ~ t0.17, TH = 520 °C), while the time dependencies were much smaller than that predicted by the classical Lifshitz-Slyozov-Wagner (LSW) theory (D ~ t1/3) and the higher TH leads to the smaller growth exponent.