Visible Luminescence From Pbs Quantum Dots Prepared By A Colloidal Method

We have investigated the synthesis of PbS quantum dots (QDs) by a colloidal method and the temperature dependence of absorption and luminescence properties. The QDs of PbS were grown with different disperse agents and growth temperatures. Preparation of PbS QDs having a narrow size distribution is succeeded in polyvinyl alcohol solutions with the optimum condition. In the visible region, both absorption and luminescence peaks are clearly observed. It is found that the temperature dependence of the absorption energy in QDs is quite different from that in a bulk crystal. We discuss the above finding from the aspect of thermal expansion effects on the quantum confinement in QDs.