# Exciton Transfer in Array of Epitaxially Connected Nanocrystals

## TL;DR

This paper introduces a new exciton transfer mechanism called tandem tunneling in epitaxially connected nanocrystals, which surpasses traditional F"orster and Dexter transfer rates, especially in silicon.

## Contribution

It proposes a third exciton transfer mechanism, tandem tunneling, providing a deeper understanding of exciton dynamics in connected nanocrystals.

## Key findings

- Tandem tunneling rate exceeds Dexter rate.
- In silicon, tandem tunneling surpasses F"orster transfer.
- New mechanism enhances exciton transfer efficiency.

## Abstract

Recently, epitaxially connected at facets semiconductor nanocrystals (NCs) have been introduced to fascilitate the electron transport between nanocrystals. To fully deploy their potential a better understanding of the exciton transfer between connected NCs is needed. We go beyond the two well-known transfer mechanisms suggested by F\"orster and Dexter and propose a third mechanism of exciton tandem tunneling. The tandem tunnelling occurs through the intermediate state in which electron and hole are in different NCs. The corresponding rate for exciton hops is larger than the Dexter rate and for Si is even much larger that the F\"orster one.