Quantum Dot Photoactivation: Mechanisms of Photostability of InP/ZnS Core/Shell Quantum Dots
Quantum dots are semiconductor nanocrystals that exhibit unique optical characteristics such as size tunability and broad absorption with applications in biomedical imaging and display technologies. Cadmium-based quantum dots have been widely used as the standard in commercial applications, but their toxic nature poses a significant challenge that needs to be addressed. Of particular interest is the study of indium-based quantum dots, due to their similar optical properties and lower toxicity. Before indium containing quantum dots can be used in optical and biological applications, we need to understand the complicated mechanisms behind their photostability. It has been observed that quantum dots can behave in unpredictable manners in response to light absorption, hindering their development. In this thesis, we add to the body of work surrounding the photostability of indium-based quantum dots, with a focus on their behavior in aqueous environment which is of relevance to their application in biological systems. We studied the photostability of InP/ZnS core/shell quantum dots in organic solvents where they are synthesized and expanded into aqueous environments through modification of the surface chemistry. Our findings show that the behavior of these quantum dots under light exposure depends on the solvent, presence of oxygen, and pH. We have also revealed that consideration of the surface ligand is important in the design of quantum dots. These results suggest that the interaction between quantum dots and light is complex and multi-mechanistic. While this study sheds light on the chemical interactions involved, further research is still necessary.
Quantum Dot, Photoactivation, Photostability, Nanoparticle, Photobleaching, Ligand
Sikkema, T. (2023). Quantum dot photoactivation: mechanisms of photostability of InP/ZnS core/shell quantum dots (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.