| Autor: |
Frank Volmer, Manfred Ersfeld, Paulo E. Faria Junior, Lutz Waldecker, Bharti Parashar, Lars Rathmann, Sudipta Dubey, Iulia Cojocariu, Vitaliy Feyer, Kenji Watanabe, Takashi Taniguchi, Claus M. Schneider, Lukasz Plucinski, Christoph Stampfer, Jaroslav Fabian, Bernd Beschoten |
| Jazyk: |
angličtina |
| Rok vydání: |
2023 |
| Předmět: |
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| Zdroj: |
npj 2D Materials and Applications, Vol 7, Iss 1, Pp 1-10 (2023) |
| Druh dokumentu: |
article |
| ISSN: |
2397-7132 |
| DOI: |
10.1038/s41699-023-00420-1 |
| Popis: |
Abstract Transition metal dichalcogenides (TMDs) have attracted much attention in the fields of valley- and spintronics due to their property of forming valley-polarized excitons when illuminated by circularly polarized light. In TMD-heterostructures it was shown that these electron-hole pairs can scatter into valley-polarized interlayer exciton states, which exhibit long lifetimes and a twist-angle dependence. However, the question how to create a valley polarization of free charge carriers in these heterostructures after a valley selective optical excitation is unexplored, despite its relevance for opto-electronic devices. Here, we identify an interlayer transfer mechanism in twisted WSe2/MoSe2 heterobilayers that transfers the valley polarization from excitons in WSe2 to free charge carriers in MoSe2 with valley lifetimes of up to 12 ns. This mechanism is most efficient at large twist angles, whereas the valley lifetimes of free charge carriers are surprisingly short for small twist angles, despite the occurrence of interlayer excitons. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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