Electrically coupled quantum dots (QDs) can support unique optoelectronic properties arising from the superposition of single-particle excited states. Experimental methods for integrating colloidal QDs within the same nano-object, however, have remained elusive to the rational design. Here, we demonstrate a chemical strategy that allows for the assembling of colloidal QDs into coupled composites, where proximal interactions give rise to unique optoelectronic behavior. The assembly method employing “adhesive” surfactants was used to fabricate both homogeneous (e.g., CdS–CdS, PbS–PbS, CdSe–CdSe) and heterogeneous (e.g., PbS–CdS, CdS–CdSe) nanoparticle assemblies, exhibiting quasi-one-dimensional exciton fine structure. In addition, tunable mixing of single-particle exciton states was achieved for dimer-like assemblies of CdSe/CdS core–shell nanocrystals. The nanoparticle assembly mechanism was explained within the viscoelastic interaction theory adapted for molten-surface colloids. Furthermore, we expect that the present work will provide the synthetic and theoretical foundation needed for building assemblies of many inorganic nanocrystals.
Cassidy, James, et al. "Tuning the Dimensionality of Excitons in Colloidal Quantum Dot Molecules." Nano Letters, vol. 21, no. 17, Aug. 2021. https://doi.org/10.1021/acs.nanolett.1c02540
@article{osti_1831437,
author = {Cassidy, James and Yang, Mingrui and Harankahage, Dulanjan and Porotnikov, Dmitry and Moroz, Pavel and Razgoniaeva, Natalia and Ellison, Cole and Bettinger, Jacob and Ehsan, Shafqat and Sanchez, John and others},
title = {Tuning the Dimensionality of Excitons in Colloidal Quantum Dot Molecules},
annote = {Electrically coupled quantum dots (QDs) can support unique optoelectronic properties arising from the superposition of single-particle excited states. Experimental methods for integrating colloidal QDs within the same nano-object, however, have remained elusive to the rational design. Here, we demonstrate a chemical strategy that allows for the assembling of colloidal QDs into coupled composites, where proximal interactions give rise to unique optoelectronic behavior. The assembly method employing “adhesive” surfactants was used to fabricate both homogeneous (e.g., CdS–CdS, PbS–PbS, CdSe–CdSe) and heterogeneous (e.g., PbS–CdS, CdS–CdSe) nanoparticle assemblies, exhibiting quasi-one-dimensional exciton fine structure. In addition, tunable mixing of single-particle exciton states was achieved for dimer-like assemblies of CdSe/CdS core–shell nanocrystals. The nanoparticle assembly mechanism was explained within the viscoelastic interaction theory adapted for molten-surface colloids. Furthermore, we expect that the present work will provide the synthetic and theoretical foundation needed for building assemblies of many inorganic nanocrystals.},
doi = {10.1021/acs.nanolett.1c02540},
url = {https://www.osti.gov/biblio/1831437},
journal = {Nano Letters},
issn = {ISSN 1530-6984},
number = {17},
volume = {21},
place = {United States},
publisher = {American Chemical Society},
year = {2021},
month = {08}}