Enhanced solar photocurrent using a quantum dot molecule

TL;DR

This study investigates how coherent tunneling in quantum dot molecules enhances solar photocurrent and power output, demonstrating up to 30% power increase and thermodynamic consistency.

Contribution

It provides a detailed analysis of coherence effects in quantum dot molecules and their impact on photovoltaic efficiency, highlighting the role of tunneling and band alignment.

Findings

Quantum dot molecules can deliver up to 30% more power than single quantum dots.

Coherence effects are consistent with the Second Law of Thermodynamics.

Tunneling and band alignment significantly influence photovoltaic performance.

Abstract

In this paper we make a detailed study of the role of coherent tunneling, on the photocurrent and power delivered by a quantum dot molecule (QDM) in the presence of solar light. We focus our analysis on the coherence driven by tunneling and its impact on the photovoltaic properties of the QDM. The coherence developed by the system raises as a resource from the interplay between the strength of the tunneling coupling, the QDM band alignment, and the coupling rates with the reservoirs of thermal phonons. Our results show that a QDM can deliver up to 30% more power than a single quantum dot, and our calculations of efficiency show coherence effects, which are consistent with the Second Law of Thermodynamics.