Resonance Raman Studies of Silicon Quantum Dot-Organic Molecule Systems
Quantum dots are semiconductor nanoparticles that are able to absorb and emit light in different colors based on their size. Found in everyday items like the screens of electronic devices, quantum dots are commonly made of cadmium, which can be toxic to humans and release harmful byproducts into the environment as they age. For this reason, quantum dots made of nontoxic elements, like silicon, have received increased attention and innovation in recent years. Silicon quantum dots are especially useful as they are tunable through the addition of organic surface species, without having to change their size. This project analyzes the properties of two silicon quantum dot-organic molecule systems to explore whether or not those properties are related to their ability to exhibit circularly polarized luminescence. The systems analyzed are silicon quantum dots with attached methoxy-binaphthalene surface species. One system is attached via an alkyne group, and the other is attached at two points via two alkyne groups. Our collaborators have found that the system attached via two alkyne groups exhibits circularly polarized luminescence, while the system attached with only one alkyne group does not. This project uses Raman spectroscopy to analyze both systems to find out if there is any observable property that may indicate why only one system exhibits CPL.