Fig. 7: Impedance measurements of the GeSn bilayer.
From: Covalent bonded bilayers from germanene and stanene with topological giant capacitance effects
Complex impedance of the GeSn bilayer in the frequency range f = 1−100 Hz. Open symbols refer to GeSn bilayer grown by e-beam method, while closed symbols denote those produced by ALD. a Real and imaginary parts of the complex impedance \({Z}^{{\prime} }\) (circles) and Z″ (triangles) as a function of frequency ω = 2πf. b Nyquist plot: experimental values of Z″ plotted against \({Z}^{{\prime} }\) (squares); Z″ and \({Z}^{{\prime} }\) determined from the RC model (stars). c Schematic representation for the local dipole and charge density q formation at the GeSn bilayer to Al2O3 interface. The sum contribution of the local dipoles may be modelled as a parallel RC circuit.
