Oleg Prezhdo of the University of Washington is supported by an award from the Theory, Models and Computational Methods program for the development of novel simulations approaches for nonadiabatic and semiclassical molecular dynamics, their implementation within time-domain density functional theory and the investigation of the fundamental questions posed in the recent time-resolved experiments performed on nanoscale materials. This work provides a detailed, atomistic picture of photo excitation dynamics in real-time and in direct connection with experiment. The research focuses on the quantum properties of condensed phase environments at the nanoscale, such as decoherence, state-specific dynamics, zero-point energy, and non-adiabatic transitions, providing more rigorous treatments of ultrafast phenomena. These methods are applied to the excitation dynamics in novel nanomaterials, including wet-electrons, carbon nanotubes and nanoribbons, and metallic particles.
The PI and his coworkers develop methods to study many important features of nanoscale systems. These studies are the first to provide the highly desirable details and understanding of many experimentally observed phenomena, generating the theoretical basis for the development of novel devices for solar energy conversion, electronics, and imaging. The PI also develops novel teaching tools for use both in introductory and advanced chemistry courses.
We have developed novel theoretical methodologies for studying ultrafast non-equilibrium processes in condensed matter and nanoscale chemical systems. With current technology, many of the newly proposed and developed materials and devices take advantage of system miniaturization and accelerated performance. Rational design of such systems requires theoretical understanding and modeling, motivating our methods development efforts. The developed theoretical methodologies were applied to study photo-induced chemical dynamics that govern a variety of energy, electronics and medical applications. The processes studied include conversion of solar energy into electricity, conversion of solar energy into chemical energy, electric charge storage, rapid electronic DNA sequencing, intracellular drug delivery, and ozone layer chemistry. We were able to propose more efficient and less expensive nanoscale materials for solar cells, batteries and capacitors. Examples include organic/inorganic hybrid systems, such as TiO2/polymer, TiO2/graphene, quantum-dot/molecule, quantum-dot/fullerene, and carbon nanotube/polymer hybrids. We demonstrated how a single photon can be converted into two or more positive and negative charge pairs, by processes known as multiple exciton generation and singlet fission. We showed how the unique physical properties of carbon nanotubes can be used to deliver polar drugs through apolar cell membranes. We gave a proof-of-principle of a graphene-based device that is capable of high-throughput DNA sequencing. Our research was highlighted in news media, including New Scientist magazine, several radio and television interviews, virtual journals, and internet exposure.
