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Department of Inorganic Chemistry, University of Chemistry and Technology Prague, 166 28 Prague 6, Czech Republic
Institute of Electrical and Microengineering, & Institute of Materials Science and Engineering, École Polytechnique
Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
Institute of Physics of the Czech Academy of Sciences, 162 00 Prague 6, Czech Republic
Institute of Microelectronics, TU Wien, 1040 Wien, Austria
Institut für Angewandte Physik,
TU Wien, 1040 Wien, Austria
van der Waals heterostructures of two-dimensional materials have unveiled frontiers in condensed matter physics, unlocking unexplored possibilities in electronic and photonic device applications. However, the investigation of wide-gap, high-κ layered dielectrics for devices based on van der Waals structures has been relatively limited. In this work, we demonstrate an easily reproducible synthesis method for the rare-earth oxyhalide LaOBr, and we exfoliate it as a 2D layered material with a measured static dielectric constant of 9 and a wide bandgap of 5.3 eV. Furthermore, our research demonstrates that LaOBr can be used as a high-κ dielectric in van der Waals field-effect transistors with high performance and low interface defect concentrations. Additionally, it proves to be an attractive choice for electrical gating in excitonic devices based on 2D materials. Our work demonstrates the versatile realization and functionality of 2D systems with wide-gap and high-κ van der Waals dielectric environments.
Corresponding author: Zdeněk Sofer. Reprints also avialable from Ulrike Diebold (diebold).
You can download a PDF file of this open-access article from ACS Nano or from the IAP/TU Wien web server.