Theory and simulation of quantum photovoltaic devices based on the non-equilibrium Green's function formalism

TL;DR

This paper reviews the application of the non-equilibrium Green's function formalism to simulate quantum photovoltaic devices, highlighting new theoretical approaches and demonstrating insights through specific device examples.

Contribution

It introduces novel theoretical methods for simulating quantum photovoltaic devices using NEGF, including processes like excitonic absorption and defect-related recombination.

Findings

Simulation of quantum well photodiode reveals detailed charge transport mechanisms.

Superlattice absorber modeling shows potential efficiency improvements.

New approaches enable comprehensive understanding of elementary photovoltaic processes.

Abstract

This article reviews the application of the non-equilibrium Green's function formalism to the simulation of novel photovoltaic devices utilizing quantum confinement effects in low dimensional absorber structures. It covers well-known aspects of the fundamental NEGF theory for a system of interacting electrons, photons and phonons with relevance for the simulation of optoelectronic devices and introduces at the same time new approaches to the theoretical description of the elementary processes of photovoltaic device operation, such as photogeneration via coherent excitonic absorption, phonon-mediated indirect optical transitions or non-radiative recombination via defect states. While the description of the theoretical framework is kept as general as possible, two specific prototypical quantum photovoltaic devices, a single quantum well photodiode and a silicon-oxide based superlattice absorber, are used to illustrated the kind of unique insight that numerical simulations based on the theory are able to provide.