scholarly journals Purely one-dimensional ferroelectricity and antiferroelectricity from van der Waals niobium oxide trihalides

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Lei Zhang ◽  
Cheng Tang ◽  
Stefano Sanvito ◽  
Aijun Du
Keyword(s):  
Electric Fields ◽  
Van Der Waals ◽  
Electronic Devices ◽  
Ferroelectric Materials ◽  
Channel Structure ◽  
One Dimensional ◽  
Ferroelectricity And Antiferroelectricity ◽  
Switching Barriers ◽  
Double Channel ◽  
Ferroelectric Switching

AbstractIntrinsic one-dimensional (1D) ferroelectric materials are rarely reported but are highly sought to break the size limit of nanostructured conventional ferroelectrics. Herein, we report a class of inborn 1D ferroelectric nanowires, namely 1D NbOX3 (X = Cl, Br, and I), that can be directly obtained from experimentally realized van der Waals crystals. In addition to the sizable spontaneous polarization, 1D NbOX3 exhibits low ferroelectric switching barriers, small coercive electric fields, and high critical temperature, governed by the hybridization of the Nb empty d orbitals and the O p orbitals (d0 rule). Moreover, the double-channel structure of 1D NbOX3 also enables the emergence of 1D antiferroelectric metastable states. Our findings not only propose a class of 1D ferroelectric materials toward the development of miniaturized and high-density electronic devices, but also pave an avenue of obtaining intrinsic 1D ferroelectrics from van der Waals crystals.

scholarly journals Moiré excitons in defective van der Waals heterostructures

2021 ◽  
Vol 118 (32) ◽  
pp. e2105468118
Author(s):  
Hongli Guo ◽  
Xu Zhang ◽  
Gang Lu
Keyword(s):  
Electric Fields ◽  
Single Photon ◽  
Van Der Waals ◽  
Energy Charge ◽  
Defect Engineering ◽  
One Dimensional ◽  
Competition And Cooperation ◽  
Ordered Arrays ◽  
Promising Strategy ◽  
Single Photon Emitters

Excitons can be trapped by moiré potentials in van der Waals (vdW) heterostructures, forming ordered arrays of quantum dots. Excitons can also be trapped by defect potentials as single photon emitters. While the moiré and defect potentials in vdW heterostructures have been studied separately, their interplay remains largely unexplored. Here, we perform first-principles calculations to elucidate the interplay of the two potentials in determining the optoelectronic properties of twisted MoS2/WS2 heterobilayers. The binding energy, charge density, localization, and hybridization of the moiré excitons can be modulated by the competition and cooperation of the two potentials. Their interplay can also be tuned by vertical electric fields, which can either de-trap the excitons or strongly localize them. One can further tailor the interplay of the two potentials via defect engineering to create one-dimensional exciton lattices with tunable orientations. Our work establishes defect engineering as a promising strategy to realize on-demand optoelectronic responses.

scholarly journals Suppressing the ferroelectric switching barrier in hybrid improper ferroelectrics

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Shutong Li ◽  
Turan Birol
Keyword(s):  
Phase Diagram ◽  
Phase Transitions ◽  
First Principles ◽  
Coercive Field ◽  
Ferroelectric Materials ◽  
Biaxial Strain ◽  
Design Strategies ◽  
Strain Tolerance ◽  
Switching Barriers ◽  
Ferroelectric Switching

Abstract Integration of ferroelectric materials into novel technological applications requires low coercive field materials, and consequently, design strategies to reduce the ferroelectric switching barriers. In this first principles study, we show that biaxial strain, which has a strong effect on the ferroelectric ground states, can also be used to tune the switching barrier of hybrid improper ferroelectric Ruddlesden–Popper oxides. We identify the region of the strain-tolerance factor phase diagram where this intrinsic barrier is suppressed, and show that it can be explained in relation to strain-induced phase transitions to nonpolar phases.

Printed Electronic Devices with Inks of TiS3 Quasi-One-Dimensional van der Waals Material

2021 ◽  
Vol 13 (39) ◽  
pp. 47033-47042
Author(s):  
Saba Baraghani ◽  
Jehad Abourahma ◽  
Zahra Barani ◽  
Amirmahdi Mohammadzadeh ◽  
Sriharsha Sudhindra ◽  
...  
Keyword(s):  
Van Der Waals ◽  
Electronic Devices ◽  
One Dimensional

Electron-Mirror Microscopic Aspects of Ferroelectric Domains of BaTiO3 And Ca2Sr (C2H5CO2)6

1970 ◽  
Vol 28 ◽  
pp. 478-479
Author(s):  
Teruo Someya ◽  
Jinzo Kobayashi
Keyword(s):  
Surface Layer ◽  
Electric Fields ◽  
Quantitative Study ◽  
Recent Progress ◽  
Ferroelectric Domain ◽  
Resolving Power ◽  
Surface Pattern ◽  
Crystal Surfaces ◽  
One Dimensional ◽  
Ferroelectric Domains

Recent progress in the electron-mirror microscopy (EMM), e.g., an improvement of its resolving power together with an increase of the magnification makes it useful for investigating the ferroelectric domain physics. English has recently observed the domain texture in the surface layer of BaTiO3. The present authors ) have developed a theory by which one can evaluate small one-dimensional electric fields and/or topographic step heights in the crystal surfaces from their EMM pictures. This theory was applied to a quantitative study of the surface pattern of BaTiO3).

scholarly journals High performance self-powered photodetector based on 1D Te-2D WS2 mixed-dimensional heterostructure

2021 ◽  
Author(s):  
Lixiang Han ◽  
Mengmeng Yang ◽  
Peiting Wen ◽  
Wei Gao ◽  
nengjie huo ◽  
...  
Keyword(s):  
High Performance ◽  
Van Der Waals ◽  
Sharp Interface ◽  
Two Dimensional ◽  
High Quality ◽  
One Dimensional ◽  
Self Powered

One dimensional (1D)-two dimensional (2D) van der Waals (vdWs) mixed-dimensional heterostructures with advantages of atomically sharp interface, high quality and good compatibility have attracted tremendous attention in recent years. The...

Kinetics-Driven One-Dimensional Growth of van der Waals Layered SnSe

2021 ◽  
Author(s):  
Zhibin Liu ◽  
Keda Ding ◽  
Zhifu Liu ◽  
Faqiang Zhang ◽  
Huarong Zeng ◽  
...  
Keyword(s):  
Van Der Waals ◽  
One Dimensional ◽  
Dimensional Growth

On the theory of electrohydrodynamically driven capillary jets

1997 ◽  
Vol 335 ◽  
pp. 165-188 ◽  
Author(s):  
ALFONSO M. GAÑÁN-CALVO
Keyword(s):  
Surface Charge ◽  
Electric Fields ◽  
Gas Flow ◽  
Wave Speed ◽  
Propagation Speed ◽  
Field Equations ◽  
Steady Regime ◽  
One Dimensional ◽  
Relaxation Effects ◽  
Capillary Jets

Electrohydrodynamically (EHD) driven capillary jets are analysed in this work in the parametrical limit of negligible charge relaxation effects, i.e. when the electric relaxation time of the liquid is small compared to the hydrodynamic times. This regime can be found in the electrospraying of liquids when Taylor's charged capillary jets are formed in a steady regime. A quasi-one-dimensional EHD model comprising temporal balance equations of mass, momentum, charge, the capillary balance across the surface, and the inner and outer electric fields equations is presented. The steady forms of the temporal equations take into account surface charge convection as well as Ohmic bulk conduction, inner and outer electric field equations, momentum and pressure balances. Other existing models are also compared. The propagation speed of surface disturbances is obtained using classical techniques. It is shown here that, in contrast with previous models, surface charge convection provokes a difference between the upstream and the downstream wave speed values, the upstream wave speed, to some extent, being delayed. Subcritical, supercritical and convectively unstable regions are then identified. The supercritical nature of the microjets emitted from Taylor's cones is highlighted, and the point where the jet switches from a stable to a convectively unstable regime (i.e. where the propagation speed of perturbations become zero) is identified. The electric current carried by those jets is an eigenvalue of the problem, almost independent of the boundary conditions downstream, in an analogous way to the gas flow in convergent–divergent nozzles exiting into very low pressure. The EHD model is applied to an experiment and the relevant physical quantities of the phenomenon are obtained. The EHD hypotheses of the model are then checked and confirmed within the limits of the one-dimensional assumptions.

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