Artificial two-dimensional polar metal by charge transfer to a ferroelectric insulator

Abstract Integrating multiple properties in a single system is crucial for the continuous developments in electronic devices. However, some physical properties are mutually exclusive in nature. Here, we report the coexistence of two seemingly mutually exclusive properties-polarity and two-dimensional conductivity-in ferroelectric Ba0.2Sr0.8TiO3 thin films at the LaAlO3/Ba0.2Sr0.8TiO3 interface at room temperature. The polarity of a ∼3.2 nm Ba0.2Sr0.8TiO3 thin film is preserved with a two-dimensional mobile carrier density of ∼0.05 electron per unit cell. We show that the electronic reconstruction resulting from the competition between the built-in electric field of LaAlO3 and the polarization of Ba0.2Sr0.8TiO3 is responsible for this unusual two-dimensional conducting polar phase. The general concept of exploiting mutually exclusive properties at oxide interfaces via electronic reconstruction may be applicable to other strongly-correlated oxide interfaces, thus opening windows to new functional nanoscale materials for applications in novel nanoelectronics.

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A tetragonal phase Mn2B2 sheet: a stable room temperature ferromagnet with sizable magnetic anisotropy

Physical Chemistry Chemical Physics ◽

10.1039/d0cp00503g ◽

2020 ◽

Vol 22 (19) ◽

pp. 10893-10899 ◽

Cited By ~ 1

Author(s):

Yusuf Zuntu Abdullahi ◽

Zeynep Demir Vatansever ◽

Ethem Aktürk ◽

Ümit Akıncı ◽

Olcay Üzengi Aktürk

Keyword(s):

Magnetic Properties ◽

Magnetic Anisotropy ◽

Tetragonal Phase ◽

Room Temperature ◽

Electronic Devices ◽

Two Dimensional ◽

Metal Boride

Exploring the magnetic properties of two-dimensional (2D) metal boride (MBene) sheets for spin-based electronics is gaining importance for developing electronic devices.

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Accurate Dry Etching with Fluorinated Gas for Two-dimensional Si Photonic Crystal

MRS Proceedings ◽

10.1557/proc-637-e1.8 ◽

2000 ◽

Vol 637 ◽

Cited By ~ 2

Author(s):

Chiharu Takahashi ◽

Jun-Ichi Takahashi ◽

Masaya Notomi ◽

Itaru Yokohama

Keyword(s):

Photonic Crystal ◽

Room Temperature ◽

High Selectivity ◽

Photonic Band Gap ◽

Electronic Devices ◽

Dry Etching ◽

Two Dimensional ◽

Ecr Plasma ◽

Etching Mask ◽

Photonic Band

AbstractAnisortopic Si dry etching is usually carried out with chlorinated gases for electronic devices such as Si-LSIs. We had another look at Si dry etching with fluorinated gases in order to obtain an ideal air hole for two-dimensional Si photonic crystal. We simulated vertical Si etching, and showed the possibility that single crystal Si can be etched vertically with high selectivity to the etching mask using fluorinated gases. We investigated ECR etching with an SF6-CF4 mixture, and vertical Si etching was achieved at room temperature. High Si/Ni selectivity above 100 was also obtained. Two-dimensional Si photonic crystal with a photonic band gap between 1.25 and 1.51 μm was produced using SF6-CF4 ECR plasma and a thin Ni mask.

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Tuning the conductivity threshold and carrier density of two-dimensional electron gas at oxide interfaces through interface engineering

AIP Advances ◽

10.1063/1.4929772 ◽

2015 ◽

Vol 5 (8) ◽

pp. 087171

Author(s):

H. J. Harsan Ma ◽

S. W. Zeng ◽

A. Annadi ◽

Z. Huang ◽

T. Venkatesan ◽

...

Keyword(s):

Carrier Density ◽

Electron Gas ◽

Two Dimensional ◽

Interface Engineering ◽

Dimensional Electron ◽

Two Dimensional Electron Gas ◽

Oxide Interfaces ◽

Dimensional Electron Gas

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Room Temperature Formation of High-Mobility Two-Dimensional Electron Gases at Crystalline Complex Oxide Interfaces

Advanced Materials ◽

10.1002/adma.201304634 ◽

2013 ◽

Vol 26 (9) ◽

pp. 1462-1467 ◽

Cited By ~ 45

Author(s):

Y. Z. Chen ◽

N. Bovet ◽

T. Kasama ◽

W. W. Gao ◽

S. Yazdi ◽

...

Keyword(s):

Room Temperature ◽

High Mobility ◽

Complex Oxide ◽

Two Dimensional ◽

Dimensional Electron ◽

Crystalline Complex ◽

Electron Gases ◽

Oxide Interfaces

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Observation of two-dimensional hole gas with mobility and carrier density exceeding those of two-dimensional electron gas at room temperature in the SiGe heterostructures

Applied Physics Letters ◽

10.1063/1.2773744 ◽

2007 ◽

Vol 91 (8) ◽

pp. 082108 ◽

Cited By ~ 41

Author(s):

M. Myronov ◽

K. Sawano ◽

Y. Shiraki ◽

T. Mouri ◽

K. M. Itoh

Keyword(s):

Carrier Density ◽

Room Temperature ◽

Electron Gas ◽

Two Dimensional ◽

Dimensional Electron ◽

Two Dimensional Electron Gas ◽

Dimensional Electron Gas

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Polymorphic gallium for active resonance tuning in photonic nanostructures: from bulk gallium to two-dimensional (2D) gallenene

Nanophotonics ◽

10.1515/nanoph-2020-0314 ◽

2020 ◽

Vol 9 (14) ◽

pp. 4233-4252

Author(s):

Yael Gutiérrez ◽

Pablo García-Fernández ◽

Javier Junquera ◽

April S. Brown ◽

Fernando Moreno ◽

...

Keyword(s):

Optical Properties ◽

Room Temperature ◽

Phase Change Materials ◽

Two Dimensional ◽

Active Materials ◽

Promising Candidate ◽

Plasmonic Structures ◽

Resonance Tuning ◽

The Many ◽

Optical Behavior

AbstractReconfigurable plasmonics is driving an extensive quest for active materials that can support a controllable modulation of their optical properties for dynamically tunable plasmonic structures. Here, polymorphic gallium (Ga) is demonstrated to be a very promising candidate for adaptive plasmonics and reconfigurable photonics applications. The Ga sp-metal is widely known as a liquid metal at room temperature. In addition to the many other compelling attributes of nanostructured Ga, including minimal oxidation and biocompatibility, its six phases have varying degrees of metallic character, providing a wide gamut of electrical conductivity and optical behavior tunability. Here, the dielectric function of the several Ga phases is introduced and correlated with their respective electronic structures. The key conditions for optimal optical modulation and switching for each Ga phase are evaluated. Additionally, we provide a comparison of Ga with other more common phase-change materials, showing better performance of Ga at optical frequencies. Furthermore, we first report, to the best of our knowledge, the optical properties of liquid Ga in the terahertz (THz) range showing its broad plasmonic tunability from ultraviolet to visible-infrared and down to the THz regime. Finally, we provide both computational and experimental evidence of extension of Ga polymorphism to bidimensional two-dimensional (2D) gallenene, paving the way to new bidimensional reconfigurable plasmonic platforms.

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A thin, deformable, high-performance supercapacitor implant that can be biodegraded and bioabsorbed within an animal body

Science Advances ◽

10.1126/sciadv.abe3097 ◽

2021 ◽

Vol 7 (2) ◽

pp. eabe3097

Author(s):

Hongwei Sheng ◽

Jingjing Zhou ◽

Bo Li ◽

Yuhang He ◽

Xuetao Zhang ◽

...

Keyword(s):

High Performance ◽

Electronic Devices ◽

Form Factors ◽

Time Frame ◽

Water Soluble ◽

Two Dimensional ◽

Medical Electronics ◽

Thin Structure ◽

Shed Light

It has been an outstanding challenge to achieve implantable energy modules that are mechanically soft (compatible with soft organs and tissues), have compact form factors, and are biodegradable (present for a desired time frame to power biodegradable, implantable medical electronics). Here, we present a fully biodegradable and bioabsorbable high-performance supercapacitor implant, which is lightweight and has a thin structure, mechanical flexibility, tunable degradation duration, and biocompatibility. The supercapacitor with a high areal capacitance (112.5 mF cm−2 at 1 mA cm−2) and energy density (15.64 μWh cm−2) uses two-dimensional, amorphous molybdenum oxide (MoOx) flakes as electrodes, which are grown in situ on water-soluble Mo foil using a green electrochemical strategy. Biodegradation behaviors and biocompatibility of the associated materials and the supercapacitor implant are systematically studied. Demonstrations of a supercapacitor implant that powers several electronic devices and that is completely degraded after implantation and absorbed in rat body shed light on its potential uses.

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