Topologically protected photovoltaics in Bi nanoribbons
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arXiv
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| Hauptverfasser: | , |
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| Format: | Preprint |
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2024
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| _version_ | 1866929210390478848 |
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| author | Uría-Álvarez, Alejandro José Palacios, Juan José |
| author_facet | Uría-Álvarez, Alejandro José Palacios, Juan José |
| contents | Photovoltaic efficiency in solar cells is hindered by many unwanted effects. Radiative channels (emission of photons) sometimes mediated by non-radiative ones (emission of phonons) are principally responsible for the decrease in exciton population before charge separation can take place. Another unwanted effect is electron-hole recombination at surfaces where in-gap edge states serve as the non-radiative channels. Topological insulators (TIs), in particular the most common ones characterized by a Z2 invariant, are rarely explored from an optoelectronics standpoint, possibly because of their typically small gaps. Otherwise, they are not much different from small-gap semiconductors and excitons are also expected to be their simplest excitations. Here we show that one can take advantage of the non-radiative decay channel due to the surface states to generate a topologically protected photovoltaic current. Focusing on two-dimensional TIs, and specifically for illustration purposes on a Bi(111) monolayer, we show the potential of TI nanoribbons to generate edge charge accumulation and edge currents under illumination. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2401_07970 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Topologically protected photovoltaics in Bi nanoribbons Uría-Álvarez, Alejandro José Palacios, Juan José Mesoscale and Nanoscale Physics Materials Science Photovoltaic efficiency in solar cells is hindered by many unwanted effects. Radiative channels (emission of photons) sometimes mediated by non-radiative ones (emission of phonons) are principally responsible for the decrease in exciton population before charge separation can take place. Another unwanted effect is electron-hole recombination at surfaces where in-gap edge states serve as the non-radiative channels. Topological insulators (TIs), in particular the most common ones characterized by a Z2 invariant, are rarely explored from an optoelectronics standpoint, possibly because of their typically small gaps. Otherwise, they are not much different from small-gap semiconductors and excitons are also expected to be their simplest excitations. Here we show that one can take advantage of the non-radiative decay channel due to the surface states to generate a topologically protected photovoltaic current. Focusing on two-dimensional TIs, and specifically for illustration purposes on a Bi(111) monolayer, we show the potential of TI nanoribbons to generate edge charge accumulation and edge currents under illumination. |
| title | Topologically protected photovoltaics in Bi nanoribbons |
| topic | Mesoscale and Nanoscale Physics Materials Science |
| url | https://arxiv.org/abs/2401.07970 |