The Effect of Monomer Size on Fusion and Coupling in Colloidal Quantum Dot Molecules

Adar Levi, Bokang Hou, Omer Alon, Yonatan Ossia, Lior Verbitsky, Sergei Remennik, Eran Rabani*, Uri Banin*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


The fusion step in the formation of colloidal quantum dot molecules, constructed from two core/shell quantum dots, dictates the coupling strength and hence their properties and enriched functionalities compared to monomers. Herein, studying the monomer size effect on fusion and coupling, we observe a linear relation of the fusion temperature with the inverse nanocrystal radius. This trend, similar to that in nanocrystal melting, emphasizes the role of the surface energy. The suggested fusion mechanism involves intraparticle ripening where atoms diffuse to the reactive connecting neck region. Moreover, the effect of monomer size and neck filling on the degree of electronic coupling is studied by combined atomistic-pseudopotential calculations and optical measurements, uncovering strong coupling effects in small QD dimers, leading to significant optical changes. Understanding and controlling the fusion and hence coupling effect allows tailoring the optical properties of these nanoscale structures, with potential applications in photonic and quantum technologies.

Original languageAmerican English
Pages (from-to)11307-11313
Number of pages7
JournalNano Letters
Issue number23
StatePublished - 13 Dec 2023

Bibliographical note

Publisher Copyright:
© 2023 American Chemical Society


  • atomistic pseudopotential calculations
  • colloidal quantum dots
  • electronic coupling
  • quantum dot molecules
  • size effect


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