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We derive an effective spin-Hamiltonian accounting for the exciton fine structure in quasi-spherical zinc-blende semiconductor nanocrystals within the k · p formalism explicitly taking into account the spin-orbit split-off valence band. It is shown that, for excitons in nanocrystals made of III-V and II-VI semiconductors with fairly small spin-orbit splitting, the scaling of the electron-hole exchange interaction with the nanocrystal size insignificantly differs from the inverse nanocrystal volume law predicted within the model neglecting the spin-orbit split-off band. Numerical calculations are performed for InP nanocrystals.
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Colloidal semiconductor nanocrystals in energy transfer reactions
Excitonic energy transfer is a versatile mechanism by which colloidal semiconductor nanocrystals can interact with a variety of nanoscale species. While this process is analogous to dipole–dipole coupling in molecular systems, the corresponding energy transfer dynamics can deviate from that of molecular assemblies due to manifestations of bulk-like features in semiconductor colloids. In particular, weak exciton binding, small singlet–triplet exciton splitting, and the energy disorder across nanocrystal ensembles can all play distinctive roles in the ensuing energy conversion processes. To characterize the variety of energy transfer schemes involving nanocrystals, this feature article will discuss the latest research by both our group and other groups on the key scenarios under which nanocrystals can engage in energy transfer with other nanoparticles, organic fluorophores, and plasmonic nanostructures, highlighting potential technological benefits to be gained from such processes. We will also shed light on experimental strategies for probing the energy transfer in nanocrystal-based assemblies, with a particular emphasis on novel characterization techniques.
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- Award ID(s):
- 1710063
- PAR ID:
- 10093440
- Date Published:
- Journal Name:
- Chemical Communications
- Volume:
- 55
- Issue:
- 21
- ISSN:
- 1359-7345
- Page Range / eLocation ID:
- 3033 to 3048
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/C9CC00162J
