Effects of Na2O on the optical properties of CdSe QDs embedded in glasses

In this work, effects of Na2O concentration on the precipitation of CdSe QDs in glasses is investigated. It is found that increase in concentration of Na2O reduces the connectivity of the network of glass and decreases the sol-ubility of Se in the glass, leading to the formation of Se-related clusters and lower temperature for the precip-itation of CdSe QDs. For glasses containing lower concentration of Na2O, defect-related photoluminescence (PL) is suppressed and the overall PL changes from dual band to narrow band with tunable wavelength in the visible range. For glasses containing higher concentration of Na2O, only dual band PL is observed due to the phase separation upon high temperature heat-treatment. Results reported in this work demonstrate that modulation of the PL properties of QDs in glasses can be accessed by adjusting the composition and structure of glasses.