Anomalous photocurrent response in van der Waals heterointerface

Van der Waals interfaces are unique platforms for novel properties and functionalities. In addition to being building blocks for functionalized devices such as p-n or tunneling junctions, symmetry of the van der Waal interface has recently been attracting much attention, represented by Moiré physics or quasicrystalline structure in twisted interfaces [1-3] and pseudo landau level formation in graphene/black phosphorus heterostructures [4].
In this talk, I will focus on the photocurrent response at van der Waals interfaces. The anomalous photovoltaic effect [6], which indicates the emergence of photo-induced spontaneous current without semiconductor p-n junction nor bias voltage, is observed at the symmetry engineered interface. A potential microscopic mechanism of the anomalous photovoltaic effect will be also discussed.

[1] M. Yankowitz, et al., Nat. Phys. 8, 382 (2012).
[2] C. R. Dean, et al., Nature 497, 598 (2013).
[3] S. J. Ahn et al., Science 361, 782 (2018)
[4] Y. Cao, et al., Nature 556, 43 (2018).
[5] Y. Liu, et al., Nat. Nanotech. 13, (2013) 828.
[6] Y. J. Zhang, et al., Nature 570, 349 (2019).