Zhang Fan, Wang Zhe, Liu Lixuan, Nie Anmin, Gong Yongji, Zhu Wenguang, Tao Chenggang
Department of Physics, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, United States.
International Center for Quantum Design of Functional Materials (ICQD), Hefei National Laboratory for Physical Sciences at the Microscale, and Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences, School of Physical Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China.
J Phys Chem Lett. 2021 Dec 16;12(49):11902-11909. doi: 10.1021/acs.jpclett.1c03251. Epub 2021 Dec 8.
Domain boundaries in ferroelectric materials exhibit rich and diverse physical properties distinct from their parent materials and have been proposed for broad applications in nanoelectronics and quantum information technology. Due to their complexity and diversity, the internal atomic and electronic structure of domain boundaries that governs the electronic properties remains far from being elucidated. By using scanning tunneling microscopy and spectroscopy (STM/S) combined with density functional theory (DFT) calculations, we directly visualize the atomic structure of polar domain boundaries in two-dimensional (2D) ferroelectric β'-InSe down to the monolayer limit. We observe a double-barrier energy potential with a width of about 3 nm across the 60° tail-to-tail domain boundaries in monolayer β'-InSe. The results will deepen our understanding of domain boundaries in 2D ferroelectric materials and stimulate innovative applications of these materials.
