Perspective on Coupled Colloidal Quantum Dot Molecules

Abstract

Electronic coupling and hence hybridization of atoms serve as the basis for the rich properties of the endless library of naturally occurring molecules. Colloidal quantum dots (CQDs) manifesting quantum strong confinement, possess atomic like characteristics with s and p electronic levels, which popularized the notion of CQDs as artificial atoms. Continuing this analogy, when two atoms are close enough to form a molecule so that their orbitals start overlapping, the orbitals' energies start to split into bonding and anti-bonding states made out of hybridized orbitals. The same concept is also applicable for two fused core-shell nanocrystals in close proximity. Their band-edge states, which dictate the emitted photon energy, start to hybridize changing their electronic and optical properties. Thus, an exciting direction of artificial molecules emerges leading to a multitude of possibilities for creating a library of new hybrid nanostructures with novel optoelectronic properties with relevance towards diverse applications including quantum technologies. In a model fused core-shell homodimer molecule, the hybridization energy is strongly correlated with the extent of structural continuity, the delocalization of the exciton wavefunction, and the barrier thickness as calculated numerically. The hybridization impacts the emitted photon statistics manifesting a faster radiative decay rate, photon bunching effect, and modified Auger recombination pathway compared to the monomer artificial atoms. Future perspectives for the nanocrystals chemistry paradigm are highlighted.

References in corpus (5)

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Cited by in corpus (10)

• Neck Barrier Engineering in Quantum Dot Dimer Molecules via Intra-Particle Ripening
• Simulations of nonradiative processes in semiconductor nanocrystals
• Complete mapping of interacting charging states in single coupled colloidal quantum dot molecules
• Two Biexciton Types Coexisting in Coupled Quantum Dot Molecules
• Photon Correlations in Colloidal Quantum Dot Molecules Controlled by the Neck Barrier
• Twisting enabled charge transfer excitons in epitaxially fused quantum dot molecules
• Electric-field fluctuations as the cause of spectral instabilities in colloidal quantum dots
• Coupling Perovskite Quantum Dot Pairs in Solution using Nanoplasmonic Assembly
• Trions Stimulate Electronic Coupling in Colloidal Quantum Dot Molecules
• Sensing applied pressure by triggering electronic quantum many-body excitations in an optical waveguide