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DOE OSTI · 3023736

Charged- and Multi-Exciton Dynamics in Colloidal Quantum Dot Molecules

Florio, Diego [Consiglio Nazionale delle Ricerche (CNR), Milano (Italy). Istituto di Fotonica e Nanotecnologie (IFN); Politecnico di Milano (Italy)] (ORCID:0009000026581657)·Levi, Adar [Hebrew University of Jerusalem (Israel)] (ORCID:0000000244831573)·Hou, Bokang [University of California, Berkeley, CA (United States)] (ORCID:0000000249290067)·Scharf, Einav [Hebrew University of Jerusalem (Israel)] (ORCID:0000000150086699)·Hörmann, Martin [Politecnico di Milano (Italy)]·Rabani, Eran [University of California, Berkeley, CA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Tel Aviv University (Israel)] (ORCID:0000000320313525)·Cerullo, Giulio [Consiglio Nazionale delle Ricerche (CNR), Milano (Italy). Istituto di Fotonica e Nanotecnologie (IFN); Politecnico di Milano (Italy)] (ORCID:0000000295342702)·Banin, Uri [Hebrew University of Jerusalem (Israel)] (ORCID:0000000316982128)·Camargo, Franco V. A. [Consiglio Nazionale delle Ricerche (CNR), Milano (Italy). Istituto di Fotonica e Nanotecnologie (IFN)] (ORCID:0000000183127899)
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Abstract

Multicarrier states in quantum dots are confined to small volumes, resulting in increased nonradiative Auger recombination rates with implications for different optoelectronic applications. Recently, the fusion of two core-shell quantum dots into a dimer has provided a new physical landscape for multiexciton states, since the excitons may share a core (intradot, localized) or occupy different cores (interdot, segregated). Here, in this study, we employ transient absorption spectroscopy to investigate the multiexciton dynamics in coupled quantum dot dimers. We observe that multiexciton populations in the dimers live significantly longer in comparison to the parent monomers, in contrast to the single exciton regime. A kinetic model that accounts for the statistical differences between monomers and dimers reveals that, while intradot multiexcitons show Auger rates similar to the monomers, interdot states have reduced Auger rates. These results pave the way for the rational design of new quantum dot molecules with tailored multiexciton properties.

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Auger recombinationcolloidal quantum dotsmultiexciton dynamicsquantum dot moleculesultrafast spectroscopy

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Florio, Diego [Consiglio Nazionale delle Ricerche (CNR), Milano (Italy). Istituto di Fotonica e Nanotecnologie (IFN); Politecnico di Milano (Italy)] (ORCID:0009000026581657), Levi, Adar [Hebrew University of Jerusalem (Israel)] (ORCID:0000000244831573), Hou, Bokang [University of California, Berkeley, CA (United States)] (ORCID:0000000249290067), Scharf, Einav [Hebrew University of Jerusalem (Israel)] (ORCID:0000000150086699), Hörmann, Martin [Politecnico di Milano (Italy)], Rabani, Eran [University of California, Berkeley, CA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Tel Aviv University (Israel)] (ORCID:0000000320313525), Cerullo, Giulio [Consiglio Nazionale delle Ricerche (CNR), Milano (Italy). Istituto di Fotonica e Nanotecnologie (IFN); Politecnico di Milano (Italy)] (ORCID:0000000295342702), Banin, Uri [Hebrew University of Jerusalem (Israel)] (ORCID:0000000316982128), Camargo, Franco V. A. [Consiglio Nazionale delle Ricerche (CNR), Milano (Italy). Istituto di Fotonica e Nanotecnologie (IFN)] (ORCID:0000000183127899). 2025-09-25. Charged- and Multi-Exciton Dynamics in Colloidal Quantum Dot Molecules. https://doi.org/10.1021/acs.nanolett.5c03224

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