TY - JOUR
T1 - Covalent bonded bilayers from germanene and stanene with topological giant capacitance effects
AU - Zhang, Binglei
AU - Grassano, Davide
AU - Pulci, Olivia
AU - Liu, Yang
AU - Luo, Yi
AU - Conte, Adriano Mosca
AU - Kusmartsev, Fedor Vasilievich
AU - Kusmartseva, Anna
N1 - Publisher Copyright:
© 2023, The Author(s).
PY - 2023/12
Y1 - 2023/12
N2 - The discovery of twisted bilayer graphene with tunable superconductivity has diverted great focus at the world of twisted van der Waals heterostructures. Here we propose a paradigm for bilayer materials, where covalent bonding replaces the van der Waals interaction between the layers. On the example of germanene-stanene bilayer, we show that such systems demonstrate fascinating topological properties and manifest giant capacitance effects of the order of C = 102μ F as well as dipole-like charge densities of q = 1 − 2 × 10−4μ C cm−2, showing promise for 2D ferroelectricity. The observed unique behaviour is closely linked to transverse strain-induced buckling deformations at the bilayer/substrate interface. In alternative GeSn bilayer structures with low twist angles the strain distortions trigger rich topological defect physics. We propose that the GeSn bilayer topology may be switched locally by a substrate-strain-induced electric fields. We demonstrate an approach to fabricate covalent bilayer materials, holding vast possibilities to transform applications technologies across solar, energy and optoelectronic sectors.
AB - The discovery of twisted bilayer graphene with tunable superconductivity has diverted great focus at the world of twisted van der Waals heterostructures. Here we propose a paradigm for bilayer materials, where covalent bonding replaces the van der Waals interaction between the layers. On the example of germanene-stanene bilayer, we show that such systems demonstrate fascinating topological properties and manifest giant capacitance effects of the order of C = 102μ F as well as dipole-like charge densities of q = 1 − 2 × 10−4μ C cm−2, showing promise for 2D ferroelectricity. The observed unique behaviour is closely linked to transverse strain-induced buckling deformations at the bilayer/substrate interface. In alternative GeSn bilayer structures with low twist angles the strain distortions trigger rich topological defect physics. We propose that the GeSn bilayer topology may be switched locally by a substrate-strain-induced electric fields. We demonstrate an approach to fabricate covalent bilayer materials, holding vast possibilities to transform applications technologies across solar, energy and optoelectronic sectors.
UR - http://www.scopus.com/inward/record.url?scp=85152537988&partnerID=8YFLogxK
U2 - 10.1038/s41699-023-00381-5
DO - 10.1038/s41699-023-00381-5
M3 - Article
AN - SCOPUS:85152537988
SN - 2397-7132
VL - 7
JO - npj 2D Materials and Applications
JF - npj 2D Materials and Applications
IS - 1
M1 - 27
ER -