| Autor: |
Christian Heyn, Leonardo Ranasinghe, Ahmed Alshaikh, Carlos A. Duque |
| Jazyk: |
angličtina |
| Rok vydání: |
2023 |
| Předmět: |
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| Zdroj: |
Nanomaterials, Vol 13, Iss 10, p 1696 (2023) |
| Druh dokumentu: |
article |
| ISSN: |
2079-4991 |
| DOI: |
10.3390/nano13101696 |
| Popis: |
The optical emission of cone-shell quantum structures (CSQS) under vertical electric (F) and magnetic (B) fields is studied by means of simulations. A CSQS has a unique shape, where an electric field induces the transformation of the hole probability density from a disk into a quantum-ring with a tunable radius. The present study addresses the influence of an additional magnetic field. A common description for the influence of a B-field on charge carriers confined in a quantum dot is the Fock-Darwin model, which introduces the angular momentum quantum number l to describe the splitting of the energy levels. For a CSQS with the hole in the quantum ring state, the present simulations demonstrate a B-dependence of the hole energy which substantially deviates from the prediction of the Fock-Darwin model. In particular, the energy of exited states with a hole lh> 0 can become lower than the ground state energy with lh= 0. Because for the lowest-energy state the electron le is always zero, states with lh> 0 are optically dark due to selection rules. This allows switching from a bright state (lh= 0) to a dark state (lh> 0) or vice versa by changing the strength of the F or B field. This effect can be very interesting for trapping photoexcited charge carriers for a desired time. Furthermore, the influence of the CSQS shape on the fields required for the bright to dark state transition is investigated. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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