Collective and local energy transfer in biologically-hybridized systems of semiconductor quantum dots and metallic nanoantenna arrays

Abstract

We study polarization-dependent energy transfer and exciton dynamics in hybrid systems consisting of quantum dot bioconjugates and arrays of metallic nanoantennas. The size distribution of the quantum dots are used to investigate how excitons with different transition energies interact with the localized surface plasmon resonances (LSPRs) and collective surface lattice resonances (SLRs) supported by the arrays. We show that, depending on the projections of the electric dipoles of the quantum dots along the nanoantennas, they can interact with these resonances differently. This leads to polarization-dependent radiative and non-radiative decay of excitons, highlighting such systems can support two types of energy transfer mechanisms: (i) collective wavelength-dependent transfer of excitation energy from quantum dots to the arrays of the metallic nanoantennas via SLR (photonic-plasmonic path), and (ii) the local energy transfer to individual nanoantennas via localized surface plasmons (direct path). Our results also show that quantum dots with larger cores can have stronger interaction with SLRs. This suggests that such resonances can act as an energy drain that enhances cascaded energy transfer between quantum dots.