Thickness-dependent Dielectric Constant of Few-layer In2Se3 Nano-flakes

Abstract

The dielectric constant or relative permittivity of a dielectric material, which describes how the net electric field in the medium is reduced with respect to the external field, is a parameter of critical importance for charging and screening in electronic devices. Such a fundamental material property is intimately related to not only the polarizability of individual atoms, but also the specific atomic arrangement in the crystal lattice. In this letter, we present both experimental and theoretical investigations on the dielectric constant of few-layer In2Se3 nano-flakes grown on mica substrates by van der Waals epitaxy. A nondestructive microwave impedance microscope is employed to simultaneously quantify the number of layers and local electrical properties. The measured dielectric constant increases monotonically as a function of the thickness and saturates to the bulk value at around 6 ~ 8 quintuple layers. The same trend of layer-dependent dielectric constant is also revealed by first-principle calculations. Our results of the dielectric response, being ubiquitously applicable to layered 2D semiconductors, are expected to be significant for this vibrant research field.

15 pages, 4 figures, 1 table in Nano letters, 2015 ASAP

References in corpus (4)

• Two Dimensional Atomic Crystals
• Anomalous Lattice Vibrations of Single and Few-Layer MoS2
• Probing the Electron States and Metal-Insulator Transition Mechanisms in Atomically Thin MoS2 Based on Vertical Heterostructures
• Modeling of a Cantilever-Based Near-Field Scanning Microwave Microscope

Cited by in corpus (15)

• Out-of-plane Piezoelectricity and Ferroelectricity in Layered $\alpha$-In2Se3 Nano-flakes
• Electronic polarizability as the fundamental variable in the dielectric properties of two-dimensional materials
• A switchable diode based on room-temperature two-dimensional ferroelectric α-In2Se3 thin layers
• Electronic bandstructure of in-plane ferroelectric van der Waals ${\beta }^{\prime }-I{n}_{2}S{e}_3$
• Visualization of Surface-acoustic-wave Potential by Transmission-mode Microwave Impedance Microscopy
• Theoretical investigation of the vertical dielectric screening dependence on defects for few-layered van der Waals materials
• Opto-electronic properties of alpha-In2Se3: single-layer to bulk
• Interferometric Imaging of Nonlocal Electromechanical Power Transduction in Ferroelectric Domains
• Direct measurement of the local electrocaloric effect in 2D ferroelectric In${}_2$Se${}_3$ by Scanning Electrocaloric Thermometry
• 2-dimensional semiconductors pave the way towards dopant based quantum computing
• Monolayer-to-mesoscale modulation of the optical properties in 2D CrI3 mapped by hyperspectral microscopy
• Retrieving optical parameters of emerging van der Waals flakes
• Excitonic gap generation in thin-film topological insulators
• Many-body description of two-dimensional van der Waals ferroelectric $\alpha -$In${}_2$Se${}_3$
• Tunneling Field-Effect Junctions with WS${}_2$ barrier