Dielectric Confinement Enables Molecular Coupling in Stacked Colloidal Nanoplatelets

Abstract

We show theoretically that carriers confined in semiconductor colloidal nanoplatelets (NPLs) sense the presence of neighbor, cofacially stacked NPLs in their energy spectrum. When approaching identical NPLs, the otherwise degenerate energy levels redshift and split, forming (for large stacks) minibands of several meV width. Unlike in epitaxial structures, the molecular behavior does not result from quantum tunneling but from changes in the dielectric confinement. The associated excitonic absorption spectrum shows a rich structure of bright and dark states, whose optical activity and multiplicity can be understood from reflection symmetry and Coulomb tunneling. We predict spectroscopic signatures which should confirm the formation of molecular states, whose practical realization would pave the way to the development of nanocrystal chemistry based on NPLs.

References in corpus (3)

• Direct Observation of Controlled Coupling in an Individual Quantum Dot Molecule
• Excitons in core-only, core-shell and core-crown CdSe nanoplatelets: interplay between in-plane electron-hole correlation, spatial and dielectric confinement
• Nanoplatelets as material system between strong confinement and weak confinement

Cited by in corpus (6)

• Zone-folded longnitude acoustic phonons driving self-trapped state emission in colloidal CdSe nanoplate superlattice
• A simple variational quantum Monte Carlo-effective mass approach for excitons and trions in quantum dots
• Fourier-imaging of single self-assembled CdSe nanoplatelet chains and clusters reveals out-of-plane dipole contribution
• Nature and Control of Shakeup Processes in Colloidal Nanoplatelets
• Enhanced robustness and dimensional crossover of superradiance in cuboidal nanocrystal superlattices
• Charging of colloidal nanoplatelets: effect of Coulomb repulsion on spin and optoelectronic properties