Energy transfer from an individual quantum dot to a carbon nanotube

TL;DR

This study investigates energy transfer from quantum dots to carbon nanotubes, revealing high efficiency and variability in transfer lengths, which advances understanding of nanoscale energy transduction mechanisms.

Contribution

It provides detailed experimental evidence of resonant energy transfer between quantum dots and carbon nanotubes, highlighting the role of exciton creation locations and efficiency saturation.

Findings

Energy transfer efficiency peaks around 96%.

Large variations in energy transfer length scales observed.

Efficiency remains high despite QD aging and non-radiative relaxation.

Abstract

A detailed understanding of energy transduction is crucial for achieving precise control of energy flow in complex, integrated systems. In this context, carbon nanotubes (CNTs) are intriguing model systems due to their rich, chirality-dependent electronic and optical properties. Here, we study the quenching of fluorescence from isolated quantum dots (QDs) upon approach of individual CNTs attached to atomic force microscope probes. Precision measurements of many different CNT/QD pairs reveal behavior consistent with resonant energy transfer between QD and CNT excitons via a Fohrster-like dipole-dipole coupling. The data reveal large variations in energy transfer length scales even though peak efficiencies are narrowly distributed around 96%. This saturation of efficiency is maintained even when energy transfer must compete with elevated intrinsic non-radiative relaxation rates during QD aging. These observations suggest that excitons can be created at different locations along the CNT length, thereby resulting in self-limiting behavior.