Intercorrelated in-plane and out-of-plane ferroelectricity in ultrathin two-dimensional layered semiconductor In2Se3

Enriching the functionality of ferroelectric materials with visible-light sensitivity and multiaxial switching capability would open up new opportunities for their applications in advanced information storage with diverse signal manipulation functions. We report experimental observations of robust intra-layer ferroelectricity in two-dimensional (2D) van der Waals layered -In2Se3 ultrathin flakes at room temperature. Distinct from other 2D and conventional ferroelectrics, In2Se3 exhibits intrinsically intercorrelated out-of-plane and in-plane polarization, where the reversal of the out-of-plane polarization by a vertical electric field also induces the rotation of the in-plane polarization. Based on the in-plane switchable diode effect and the narrow bandgap (~1.3 eV) of ferroelectric In2Se3, a prototypical non-volatile memory device, which can be manipulated both by electric field and visible light illumination, is demonstrated for advancing data storage technologies.

Cui C, Hu W-J, Yan X, Addiego C, Gao W, et al. (2018) Intercorrelated In-Plane and Out-of-Plane Ferroelectricity in Ultrathin Two-Dimensional Layered Semiconductor In2Se3. Nano Letters. Available:

L.J.L. thanks the support from King Abdullah University of Science and Technology (Saudi Arabia). The work at University of California - Irvine was supported by the Department of Energy (DOE), Office of Basic Energy Sciences, Division of Materials Science and Engineering, under Grant under Grant No. DE-SC0014430, and the Irvine Materials Research Institute (IMRI). We would like to thank Dr. Toshi Aoki from IMRI for his help on S/TEM experiments.

American Chemical Society (ACS)

Nano Letters


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