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

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 CdSexTe(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) Foerster 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.