The frequency of available light is often lower than desired for a given task. For instance, low-energy light can take advantage of an optical transparency window of biological tissue and penetrate to ingested theranostic nanoparticles, but the photoactivated release of cancer drugs requires energy in the UV range. The efficiency of photochemical processes in biological systems also suffers as a result of a mismatch of existing and desired frequencies of light. For instance, microalgae used in energy harvesting strategies do not efficiently utilize the red end of the solar spectrum for biomass production. An analogous issue confronts those laser design or that are involved in the creation of solar panels that can process IR light. Motivated by such disconnects between the desired light and that available, a number of strategies have been developed to upconvert light to higher frequencies. This talk will consider one such upconversion process known as energy pooling in which the energy of two electrons in excited states is transferred to the third electron. A combination of molecular quantum electrodynamics, perturbation theory, and ab initio calculations is used to create a computational methodology capable of estimating the rate of energy pooling. The approach is applied to quantify the conditions under which the process becomes viable. It is then generalized to cavity settings to explore the possibility of increasing pooling rate through modification of the electric field modes that mediate exciton transfer.
Mark Lusk Professor of Physics Colorado School of Mines. Mark Lusk studied solid-state physics at the U.S. Naval Academy and was subsequently a naval nuclear engineer. He was a member of the engineering team that built, tested and took to sea the USS Theodore Roosevelt aircraft carrier. After an MS degree in Electrical Engineering at Colorado State University, he obtained a PhD degree in Applied Mechanics at the California Institute of Technology. He has been a professor for twenty-four years. Mark’s research focuses on theoretical and computational queries related to the excited states of nanostructured assemblies with an emphasis on quantum transport and optical interactions with matter. This frequently involves the consideration of emergent phenomena associated with photon-electron-phonon entanglement. Examples include charge transport in quantum dot assemblies, multiple exciton generation in confined structures, and up/down quantum cutting dynamics in energy conversion, laser physics and theranostics. The goal of such research is to address fundamental issues in photon-matter dynamics in collaboration with colleagues who emphasize experimental methods of inquiry. He is the lead theorist for the NSF-sponsored Renewable Energy Materials Research Science and Engineering Research Center (REMRSEC) and the lead scientist for high performance computing research at the Colorado School of Mines, an organization that he created and to which he brought several million dollars of infrastructure funding. Mark’s invited lectures have a wide international footprint, and his publications include papers published in Nature, Physical Review Letters, Nano Letters, ACS Nano and the Proceedings of the Royal Society. Other professional metrics include: · 9 patents · R&D 100 Award for Microstructure-Property Model Software – 2000 · CSM Faculty Research Excellence Award – 2012 o awarded to faculty member whose research was deemed to be most impactful in the year awarded · Distinguished CSM Faculty Member Award – 7 times o most outstanding faculty member as voted by graduating seniors · Colorado School of Mines Alumni Teaching Award – 2007 o awarded by the CSM Alumni Association for best teacher at the university in the year awarded