Simon A. Svatek
Triplet Excitation and Electroluminescence from a Supramolecular Monolayer Embedded in a Boron Nitride Tunnel Barrier
Svatek, Simon A.; Kerfoot, James; Summerfield, Alex; Nizovtsev, Anton S.; Korolkov, Vladimir V.; Taniguchi, Takashi; Watanabe, Kenji; Antolín, Elisa; Besley, Elena; Beton, Peter H.
Anton S. Nizovtsev
Vladimir V. Korolkov
Peter H. Beton
© 2019 American Chemical Society. We show that ordered monolayers of organic molecules stabilized by hydrogen bonding on the surface of exfoliated few-layer hexagonal boron nitride (hBN) flakes may be incorporated into van der Waals heterostructures with integral few-layer graphene contacts forming a molecular/two-dimensional hybrid tunneling diode. Electrons can tunnel through the hBN/molecular barrier under an applied voltage VSD, and we observe molecular electroluminescence from an excited singlet state with an emitted photon energy hν > eVSD, indicating upconversion by energies up to ∼1 eV. We show that tunneling electrons excite embedded molecules into singlet states in a two-step process via an intermediate triplet state through inelastic scattering and also observe direct emission from the triplet state. These heterostructures provide a solid-state device in which spin-triplet states, which cannot be generated by optical transitions, can be controllably excited and provide a new route to investigate the physics, chemistry, and quantum spin-based applications of triplet generation, emission, and molecular photon upconversion.
|Journal Article Type||Article|
|Publication Date||Jan 8, 2020|
|Publisher||American Chemical Society|
|Peer Reviewed||Peer Reviewed|
|APA6 Citation||Svatek, S. A., Kerfoot, J., Summerfield, A., Nizovtsev, A. S., Korolkov, V. V., Taniguchi, T., …Beton, P. H. (2020). Triplet Excitation and Electroluminescence from a Supramolecular Monolayer Embedded in a Boron Nitride Tunnel Barrier. Nano Letters, 20(1), 278-283. https://doi.org/10.1021/acs.nanolett.9b03787|
|Keywords||Mechanical Engineering; General Materials Science; Bioengineering; General Chemistry; Condensed Matter Physics|
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