Enhanced light-harvesting of protein-pigment complexes assisted by a quantum dot antenna

TL;DR

This paper predicts that attaching a quantum dot antenna to a protein-pigment complex significantly enhances its ability to harvest light, especially in spectral regions where the pigments absorb poorly, by using energy transfer mechanisms.

Contribution

It introduces a novel nanoassembly combining a quantum dot with a protein-pigment complex to improve light absorption in specific spectral regions.

Findings

Enhanced absorption in the green and orange-red bands.

Efficient energy transfer from quantum dot to dyes.

Potential for improved solar energy harvesting applications.

Abstract

We predict the enhanced light harvesting of a protein-pigment complex when assembled to a quantum dot (QD) antenna. Our prototypical nanoassembly setup is composed of a Fenna-Mattews-Olson system hosting 8 Bacteriochlorophyll (BChl) a dyes, and a near-infrared emitting CdSe$_x$Te$_{(1-x)}$/ZnS alloy-core/shell nanocrystal. BChl a has two wide windows of poor absorption in the green and orange-red bands, precisely where most of the sunlight energy lies. The selected QD is able to collect sunlight efficiently in a broader band and funnel its energy by a (non-radiative) F\"orster resonance energy transfer mechanism to the dyes embedded in the protein. By virtue of the coupling between the QD and the dyes, the nanoassembly absorption is dramatically improved in the poor absorption window of the BChl a.