Exciton tuning in monolayer WSe$_2$ via substrate induced electron doping
| Autor: | Pan, Yang, Rahaman, Mahfujur, He, Lu, Milekhin, Ilya, Manoharan, Gopinath, Aslam, Muhammad Awais, Blaudeck, Thomas, Willert, Andreas, Matković, Aleksandar, Madeira, Teresa I., Zahn, Dietrich R. T. |
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| Rok vydání: | 2022 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | We report on large exciton tuning in WSe$_2$ monolayers via substrate induced non-degenerate doping. We observe a redshift of $\sim$62 meV for the $A$ exciton together with a 1-2 orders of magnitude photoluminescence (PL) quenching when the monolayer WSe$_2$ is brought in contact with highly oriented pyrolytic graphite (HOPG) compared to the dielectric substrates such as hBN and SiO$_2$. As the evidence of doping from HOPG to WSe$_2$, a drastic increase of the trion emission intensity was observed. Using a systematic PL and Kelvin probe force microscopy (KPFM) investigation on WSe$_2$/HOPG, WSe$_2$/hBN, and WSe$_2$/graphene, we conclude that this unique excitonic behavior is induced by electron doping from the substrate. Our results propose a simple yet efficient way for exciton tuning in monolayer WSe$_2$, which plays a central role in the fundamental understanding and further device development. Comment: 14 pages, 10 figures |
| Databáze: | arXiv |
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