All-optical control of charge transfer and interlayer excitons in transition metal dichalcogenide heterostructures
| Autor: | Pavel Valencia-Acuna, Hui Zhao, Peymon Zereshki |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Condensed matter physics Exciton Charge (physics) Heterojunction 02 engineering and technology Electron Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 021001 nanoscience & nanotechnology 01 natural sciences Condensed Matter::Materials Science Electron transfer Dipole Electric field 0103 physical sciences 010306 general physics 0210 nano-technology Wave function |
| Zdroj: | Physical Review B. 103 |
| ISSN: | 2469-9969 2469-9950 |
| DOI: | 10.1103/physrevb.103.165416 |
| Popis: | An all-optical approach to control interlayer charge transfer and interlayer exciton dynamics is demonstrated using transition metal dichalcogenide heterostructures of ${\mathrm{MoSe}}_{2}/{\mathrm{MoS}}_{2}$ and ${\mathrm{MoSe}}_{2}/{\mathrm{WS}}_{2}$ as examples. In the three-pulse pump-probe experiments, a control pulse injects photocarriers and produces an electric field due to the interlayer charge separation. A pump pulse excites new carriers and their dynamics under the influence of the control-injected carriers and field is time-resolved by measuring differential reflectance of a third probe pulse. In ${\mathrm{MoSe}}_{2}/{\mathrm{MoS}}_{2}$, the interlayer electron transfer time from ${\mathrm{MoSe}}_{2}$ to ${\mathrm{MoS}}_{2}$ decreases with increasing the control-injected carrier density and electric field. The dipole moment of the interlayer excitons is reduced by the control pulse, which can be utilized for ultrafast and all-optical control of interlayer excitons. The recombination of the interlayer excitons is enhanced by the control pulse, which increases the spatial overlap of the electron and hole wave functions. The effect of the control pulse on the interlayer excitons is confirmed in the ${\mathrm{MoSe}}_{2}/{\mathrm{WS}}_{2}$ heterostructure, although its effect on the electron transfer time is not resolvable. These results reveal useful information to understand and control interlayer charge transfer dynamics and provide tools for ultrafast manipulation of electrons in van der Waals heterostructures. |
| Databáze: | OpenAIRE |
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