Investigation of indirect excitons in bulk $2H$-MoS$_2$ using transmission electron energy-loss spectroscopy
| Autor: | Habenicht, Carsten, Schuster, Roman, Knupfer, Martin, Büchner, Bernd |
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| Rok vydání: | 2018 |
| Předmět: | |
| Zdroj: | Carsten Habenicht et al 2018 J. Phys.: Condens. Matter 30 205502 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/1361-648X/aabd02 |
| Popis: | We have investigated indirect excitons in bulk $2H$-MoS$_2$ using transmission electron energy-loss spectroscopy. The electron energy-loss spectra were measured for various momentum transfer values parallel to the $\Gamma$K and $\Gamma$M directions of the Brillouin zone. The results allowed the identification of the indirect excitons between the valence band K$_{\mathrm{v}}$ and conduction band $\Lambda_{\mathrm{c}}$ points, the $\Gamma_{\mathrm{v}}$ and K$_{\mathrm{c}}$ points as well as adjacent K$_{\mathrm{v}}$ and K$^{\prime}_\textrm{c}$ points. The energy-momentum dispersions for the K$_{\mathrm{v}}$-$\Lambda_{\mathrm{c}}$, $\Gamma_{\mathrm{v}}$-K$_{\mathrm{c}}$ and K$_{\mathrm{v1}}$-K$^{\prime}_\textrm{c}$ excitons along the $\Gamma$K line are presented. The former two transitions exhibit a quadratic dispersion which allowed calculating their effective exciton masses based on the effective mass approximation. The K$_\mathrm{v1}$-K$^{\prime}_\textrm{c}$ transition follows a more linear dispersion relationship. Comment: 8 pages, 4 figures |
| Databáze: | arXiv |
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