Intensely emitting CdTe nanocrystals retained initial photoluminescence efficiency in sol–gel derived Si1-xZrxO2 glass

Emitting CdTe nanocrystals (NCs) were embedded in pure glass matrices (Si_1-xZr_xO₂, x≤0.15) using a controlled sol–gel method, where the pre-hydrolyzed condition, the molar ratio of Zr/Si, the gelation time, the pH, and the amount of alcohol were judiciously optimized considering the surface condition of the NCs and the mechanism of the glass formation. As a result, the prepared glass phosphor exhibited high photoluminescence efficiencies (40% for green and 60% for red when Zr/Si was 5–10%) by retaining their initial values as in CdTe colloidal solution. To our knowledge, these values are the highest among those ever obtained for any solid matrices containing NCs. Because of the existence of Zr, the prepared glasses exhibit much better resistance against the ambient atmosphere, heat-treatment, and boiling water compared with pure silica glass (x=0) or the glass prepared from our other methods using a silane coupling agent. Thus, the obtained glass is promising for applications such as optical devices. PACS 78.67.Bf; 78.55.Qr; 78.55.Et