Speaker
Description
"The relatively weak van der Waals bond in 2D materials has ushered in a rich new era of stacking engineering. We recently found in rhombohedrally stacked MoS2, a Berry phase contrast between layers can induce an asymmetric interlayer coupling and an out-of-plane spontaneous electrical polarization (1). The polarization direction can be switched via interlayer sliding, forming a new type of ferroelectricity. In addition, we demonstrated that such a polarization can lead to a spontaneous photovoltaic effect without any pn junctions (2). Compared to conventional PV effects, our device shows a similar quantum efficiency with an ultrafast speed and potentially a programmable polarity. The rhombohedrally stacked transition metal dichalcogenides therefore provide a new platform for studying spontaneous polarization at the atomic scale.
(1) Jing Liang, et al, arXiv:2209.06966 (2022).
(2) Dongyang Yang, et al, Nature Photonics, 16, 469–474 (2022)."
External references
- 22110064
- 85e05e81-0a7c-4112-86de-1adb2efe7c9d
- faf2031b-42e6-4f37-9ff0-78432b6678a3
