Microscopic theory to quantify the competing kinetic processes in photoexcited surface-coupled quantum dots

TL;DR

This paper develops a comprehensive microscopic theory and computational framework to analyze charge and energy transfer dynamics in photoexcited quantum dots near surfaces, with applications to photovoltaic and tunneling devices.

Contribution

It introduces a unified, first-principles-based approach combining Hamiltonian modeling and density matrix formalism for quantum dot surface interactions.

Findings

Demonstrates the framework with InAs quantum dots on Au surfaces.

Predicts diverse kinetic behaviors relevant to photovoltaic systems.

Includes non-perturbative effects of charge transitions on the electrode.

Abstract

We present a self-contained theoretical and computational framework for dynamics following photoexcitation in quantum dots near planar interfaces. A microscopic Hamiltonian parameterized by first principles calculations is merged with a reduced density matrix formalism that allows for the prediction of time-dependent charge and energy transfer processes between the quantum dot and the electrode. While treating charge and energy transfer processes on an equal footing, the non-perturbative effects of sudden charge transitions on the Fermi sea of the electrode are included. We illustrate the formalism with calculations of an InAs quantum dot coupled to the Shockley state on an Au[111] surface, and use it to concretely discuss the wide range of kinetics possible in these systems and their implications for photovoltaic systems and tunnel junction devices. We discuss the utility of this framework for the analysis of recent experiments.