Theory and Simulation of Non-adiabatic Excited State Dynamics in Nanoscale systems

University Of Southern California, Los Angeles CA

Investigators

Abstract

Professor Oleg Prezhdo of the University of Southern California is supported by an award from the Chemical Theory, Models and Computational Methods (CTMC) program in the Division of Chemistry to investigate ultrafast processes in modern nanoscale materials and devices aimed at solar energy harvesting and optoelectronic applications. Further progress in photovoltaics, photocatalysis, electronics, imaging, detection, as well as in the emerging spintronics, plasmonics, valleytronics and quantum information technologies, requires device miniaturization and involves very fast timescales. In order to advance these fields, Oleg Prezhdo’s group has pioneered and will further develop theoretical and computational methods that allow them to model the new materials and processes with atomistic precision and fine time-resolution. This modeling will mimic most closely the key phenomena as they occur in nature, provide fundamental interpretation of the experimental data, and guide future efforts in design of materials and devices. The theoretical studies are essential for advancing the technologies that are critical for our society future. Professor Oleg Prezhdo and his group will develop novel theoretical and simulation approaches for nonadiabatic molecular dynamics, implementing them within real-time time-dependent density functional theory, and investigating excited state dynamics in modern nanoscale materials and multi-component hybrids. The balanced program combining theory and applications will provide a detailed, atomistic picture of the photo-excitation dynamics in time-domain, and in direct connection and collaboration with experiment. The methods development and implementation will focus on modified Ehrenfest-type methods, Liouville-space surface hopping approaches, Lindblad and Pauli master equations with surface hopping rates, and machine learning analysis and acceleration of nonadiabatic molecular dynamics. The applications include studies of excited state dynamics in metal halide perovskites, transition metal dichalcogenides and two-dimensional materials, metallic and semiconducting quantum dots, and hybrids including several of these materials. Such materials and systems find important applications in solar energy harvesting and optoelectronics. Oleg Prezhdo’s work advances the fundamental aspects of quantum dynamics and addresses practical questions in excitation and charge transfer on the nanoscale. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.