Influence of electron-hole recombination on optical properties of boro-silicate glasses containing CdS quantum dots

Semiconductor (CdS) quantum dots were grown in a glass matrix (SiO₂-B₂O₃-ZnO-Na₂O-K₂O) by controlled heat treatment. Growth of CdS quantum dots were confirmed by optical absorption (UV–vis), photoluminescence (PL), micro-Raman spectroscopy, X-ray diffraction (XRD) and High resolution transmission electron microscopy (HRTEM). The structural modification occur in glass matrix were studied with Fourier transform infrared spectroscopy (FTIR). Clusters formation due to heat treatment was studied by field emission gun scanning electron microscopy (FEG-SEM). The observed experimental data shows that the CdS QDs size is very well controlled by single stage heat treatment. Size dependent blue shift in optical energy band gap and blue energy shift in PL intensity was observed with annealing time. The overall study of these glasses suggests these glasses are useful as an optical filters.