The fusion method was used to produce PbS quantum dots (QDs) embedded in S-doped glass matrix (SiO2-Na2CO3-Al2O3-PbO2-B2O3:S). Measurements of optical absorption (OA), photoluminescence (PL) and atomic force microscopy (AFM) have been carried out in order to characterize the produced QDs. A strong red-shift observed in the optical features with an increase of the annealing time indicates an increase in QD-size. The QD sizes predicted by k.p theoretical results were confirmed by AFM observation.

The microluminescence surface scan technique (MSST) has been used to investigate photocarrier diffusion in undoped In0.53Ga0.47 As - InP single quantum well (QW), in the temperature (T) range from 15 K to 295 K. Narrowing of the photoluminescence (PL) spatial profile is observed as the temperature is lowered, indicating reduction of the photocarrier diffusion length upon cooling. It was found that the width of the PL spatial profile follows a linear function of temperature, but a change in slope by a factor of 2.6 is observed at about 200 K, indicating a change of the dominant carrier scattering mechanism. In the temperature range of 15 K to 200 K, the ambipolar photocarrier diffusion mechanism seems to be correlated to impurity states thermally activated.