Exploring the CdTe Quantum Dots in Ionic Liquids by Employing a Luminescent Hybrid of the Two

Poor solubility of the semiconductor quantum dots (QDs) severely restricts studies on these substances in room temperature ionic liquids (ILs). It also limits applications, which require both these promising classes of materials. In this work, a simple method employing a task-specific thiol-capped imidazolium ionic liquid (SH-UMIM) is developed that allows study of luminescent CdTe QDs of different sizes in a large number of ILs. Luminescence studies based on ensemble and single-particle blinking measurements have been performed to investigate the role of the capping agent and the media (ILs) on the stability and luminescence properties of the QDs in these media. The results suggest that improved luminescence properties of the CdTe QDs in ILs is due to the capping agent, SH-UMIM, and the enhanced stability of the QDs toward molecular oxygen is provided by the ILs because of low solubility of oxygen in these viscous media.