Speaker
Description
This study investigates the application of response theory to describe excited-state electron charge dynamics, focusing on the phenomena of charge separation. We examine the strengths and limitations of linear and quadratic response theories, using a model that mimics the behavior of photovoltaic systems. While linear response theory effectively describes small perturbations, it cannot account for charge separation, which is essential in photovoltaic and photocatalytic applications. Quadratic response theory, however, enables a qualitatively more accurate modeling of charge dynamics under stronger fields of various forms, providing close agreement with exact time propagation methods. Additionally, we explore the role of Coulomb interactions and identify optimal conditions under which they enhance charge separation, demonstrating the broader potential of response theory in improving the design and performance of optoelectronic devices.