First author: Takatoshi Akamatsu, Toshiya Ideue, Ling Zhou
Corresponding author: Toshiya Ideue
Communications unit: Center for Quantum Phase Electronics and Department of Applied Physics, University of Tokyo
The van der Waals interface can be formed by stacking layers without regard to the lattice constant or the symmetry of the individual building blocks. Toshiya Ideue et al. at the University of Tokyo designed the symmetry of the van der Waals interface of tungsten selenide and black phosphorus and achieved in-plane electron polarization, which led to the emergence of spontaneous photovoltaic effects. Spontaneous photocurrents are observed in the polar direction, but not in the direction perpendicular to the vertical direction. The observed self-luminescent current can be explained by a quantum mechanical shift current that reflects the geometric and topological electronic properties of this emerging interface. The current results provide a simple guide to symmetry engineering for a variety of van der Waals interfaces.
Figure 1: Symmetry and mole stripes of the WSe2/BPvdW interface
Figure 2: Photovoltaic response in vdW crystals and interfaces with different symmetries
Figure 3: Characteristics of spontaneous photovoltaic effects in the WSe2/BP interface
Figure 4: Tight binding model of the WSe2/BP interface and its shift current
Original link:
https://science.sciencemag.org/content/372/6537/68/tab-pdf
Homepage of the research group:
http://topo-mat-sci.jp/en/members/sp/profile_c01_ideue/