Probing Fundamental Light-Matter Interactions in Colloidal Hybrid Quantum Structures for Novel Plasmon-Enhanced Solar Energy Conve
Min Ouyang, associate professor of physics, University of Maryland, College Park is attempting to understand certain aspects of an unusual phenomenon, generally known as plasmonics, as they occur in exceptionally tiny objects called nanostructures. Ouyang is working with a $100,000 Scialog grant from RCSA. “If this line of research is successful,” Ouyang said, “it could greatly improve efficiencies in the production of electricity, as well as the manufacture of burnable fuels, directly from sunlight.” A plasmon is a “quasi particle”—that is, it doesn’t exist as a fundamental particle in nature, but it is sometimes created when photons, the basic particles of light, interact in a certain way with electrons, the smallest particle inside the atom. A plasmon is basically a ripple, or wave, in the sea of electrons that exists among large groupings of metal atoms. Experts say plasmonics is the reason why ancient stained glass, made with metal compounds, glows so brightly when transmitting sunlight. Specifically Ouyang and his students will look at how plasmons join forces with another quasi particle, the exciton, which occurs when an electron and its “hole,” or the place where it should normally be in an atomic lattice, are bound together by static electricity (actually the Coulomb force). The exciton can transport energy without also transmitting charge. Ouyang’s goal is to understand the nature of recently discovered “plasmon-exiton resonant coupling,” which, as the term implies, allows the two different quasi particles to work together; in this case Ouyang theorizes such a process, if properly harnessed, might enhance a given material’s ability to absorb photons, thus potentially improving its ability to generate electrical current from sunlight.