Theory of plasmon-enhanced Foerster energy transfer in optically-excited semiconductor and metal nanoparticles

TL;DR

This paper develops a theoretical framework for understanding how plasmonic effects from metal nanocrystals can enhance and modify Foerster energy transfer between semiconductor nanoparticles, highlighting conditions for experimental observation.

Contribution

It introduces equations describing plasmon-assisted energy transfer rates, photoluminescence, and dissipation, advancing the understanding of energy transfer in hybrid nanosystems.

Findings

Plasmonic nanocrystals can increase the range and rate of Foerster transfer.

Metal nanocrystals cause increased energy dissipation during transfer.

Special conditions are required for experimental detection of the enhanced transfer.

Abstract

We describe the process of Foerster transfer between semiconductor nanoparticles in the presence of a metal subsystem (metal nanocrystals). In the presence of metal nanocrystals, the Foerster process can become faster and more long-range. The enhancement of Foerster transfer occurs due to the effect of plasmon-assisted amplification of electric fields inside the nanoscale assembly. Simultaneously, metal nanocrystals lead to an increase of energy losses during the Foerster transfer process. We derive convenient equations for the energy transfer rates, photoluminescence intensities, and energy dissipation rates in the please of plasmon resonances. Because of strong dissipation due to the metal, an experimental observation of plasmon-enhanced Foerster transfer requires special conditions. As possible experimental methods, we consider cw- and time-resolved photoluminescence studies and describe the conditions to observe plasmon-enhanced transfer. In particular, we show that the photoluminescence spectra should be carefully analyzed since the plasmon-enhanced Foerster effect can appear together with strong exciton energy dissipation. Our results can be applied to a variety of experimental nanoscale systems.