Efficient photon upconversion enabled by strong coupling between silicon quantum dots and anthracene

Kefu Wang; R Peyton Cline; Joseph Schwan; Jacob M Strain; Sean T Roberts; Lorenzo Mangolini; Joel D Eaves; Ming Lee Tang

doi:10.1038/s41557-023-01225-x

Efficient photon upconversion enabled by strong coupling between silicon quantum dots and anthracene

Nat Chem. 2023 Aug;15(8):1172-1178. doi: 10.1038/s41557-023-01225-x. Epub 2023 Jun 12.

Authors

Kefu Wang^#^{1

2}, R Peyton Cline^#³, Joseph Schwan^#⁴, Jacob M Strain⁵, Sean T Roberts⁶, Lorenzo Mangolini⁷, Joel D Eaves⁸, Ming Lee Tang^{9

10}

Affiliations

¹ Department of Chemistry, University of Utah, Salt Lake City, UT, USA.
² Department of Chemistry, University of California, Riverside, Riverside, CA, USA.
³ Department of Chemistry, University of Colorado Boulder, Boulder, CO, USA.
⁴ Department of Mechanical Engineering, University of California, Riverside, Riverside, CA, USA.
⁵ Department of Chemistry, The University of Texas at Austin, Austin, TX, USA.
⁶ Department of Chemistry, The University of Texas at Austin, Austin, TX, USA. [email protected].
⁷ Department of Mechanical Engineering, University of California, Riverside, Riverside, CA, USA. [email protected].
⁸ Department of Chemistry, University of Colorado Boulder, Boulder, CO, USA. [email protected].
⁹ Department of Chemistry, University of Utah, Salt Lake City, UT, USA. [email protected].
¹⁰ Department of Chemistry, University of California, Riverside, Riverside, CA, USA. [email protected].

^# Contributed equally.

PMID: 37308710
DOI: 10.1038/s41557-023-01225-x

Abstract

Hybrid structures formed between organic molecules and inorganic quantum dots can accomplish unique photophysical transformations by taking advantage of their disparate properties. The electronic coupling between these materials is typically weak, leading photoexcited charge carriers to spatially localize to the dot or to a molecule at its surface. However, we show that by converting a chemical linker that covalently binds anthracene molecules to silicon quantum dots from a carbon-carbon single bond to a double bond, we access a strong coupling regime where excited carriers spatially delocalize across both anthracene and silicon. By pushing the system to delocalize, we design a photon upconversion system with a higher efficiency (17.2%) and lower threshold intensity (0.5 W cm^-2) than that of a corresponding weakly coupled system. Our results show that strong coupling between molecules and nanostructures achieved through targeted linking chemistry provides a complementary route for tailoring properties in materials for light-driven applications.

Abstract

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