Colloidal quantum dot molecules manifesting quantum coupling at room temperature

Jiabin Cui,Uri Banin,Meirav Oded,Nir Waiskopf,Somnath Koley,Sergei Remennik,Inna Popov,Doaa Shamalia,Yossef E Panfil

doi:10.1038/s41467-019-13349-1

Jiabin Cui, Uri Banin + Show 7 more

Open Access

https://doi.org/10.1038/s41467-019-13349-1

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Journal: Nature Communications	Publication Date: Dec 1, 2019
Citations: 114	License type: open-access

Affiliation: Hebrew University of Jerusalem

Abstract

Coupling of atoms is the basis of chemistry, yielding the beauty and richness of molecules. We utilize semiconductor nanocrystals as artificial atoms to form nanocrystal molecules that are structurally and electronically coupled. CdSe/CdS core/shell nanocrystals are linked to form dimers which are then fused via constrained oriented attachment. The possible nanocrystal facets in which such fusion takes place are analyzed with atomic resolution revealing the distribution of possible crystal fusion scenarios. Coherent coupling and wave-function hybridization are manifested by a redshift of the band gap, in agreement with quantum mechanical simulations. Single nanoparticle spectroscopy unravels the attributes of coupled nanocrystal dimers related to the unique combination of quantum mechanical tunneling and energy transfer mechanisms. This sets the stage for nanocrystal chemistry to yield a diverse selection of coupled nanocrystal molecules constructed from controlled core/shell nanocrystal building blocks. These are of direct relevance for numerous applications in displays, sensing, biological tagging and emerging quantum technologies.

Highlights

Coupling of atoms is the basis of chemistry, yielding the beauty and richness of molecules
Colloidal semiconductor quantum dots (CQDs) that contain hundreds to thousands of atoms have reached an exquisite level of control, side by side with gaining fundamental understanding of their size, composition, and surfacecontrolled properties leading to their implementation in technological applications[1]
If one considers CQDs as artificial atom building blocks[2,3], how plentiful would be the selection of composition, properties, and functionalities of the corresponding artificial molecules? we introduce the utilization of CQDs as basic elements in “nanocrystal chemistry” for construction of coupled colloidal nanocrystals molecules focusing on homodimer quantum dots (QDs), in analogy to homonuclear diatomic molecules

Summary

Introduction

Coupling of atoms is the basis of chemistry, yielding the beauty and richness of molecules. Exemplary coupled homodimer molecules were generated from CdSe/CdS core/ shell[18,19] CQDs via a procedure utilizing silica nanoparticles (NPs) as a template for forming molecularly linked dimers[20], which are fused via a high-temperature reaction (Fig. 1a, full scheme in Supplementary Fig. 1).

Results

Conclusion