Publications related to Electret

Polarization-enhanced GaN Schottky barrier diodes: Ultra-thin InGaN for high breakdown voltage and low Ron

Elison de Nazareth Matioli, Zheng Hao, Alessandro Floriduz

In this work, we present a concept that leverages the strong piezoelectric polarization field in InGaN, which counteracts the external electric field at reverse bias. We show that despite the smaller InGaN band-gap and lower critical electric field, its st ...

2024

Ferroelectric device or structure and a method for producing ferroelectric devices or structures

Tobias Kippenberg, Rui Ning Wang, Zelin Tan

The present invention concerns a method for producing at least one ferroelectric device or structure comprising the steps of providing at least one ferroelectric material or layer, or providing at least one ferroelectric material or layer to be patterned o ...

2023

Intrinsic-Strain Engineering by Dislocation Imprint in Bulk Ferroelectrics

Dragan Damjanovic, Fangping Zhuo

We report an intrinsic strain engineering, akin to thin filmlike approaches, via irreversible hightemperature plastic deformation of a tetragonal ferroelectric single-crystal BaTiO3. Dislocations wellaligned along the [001] axis and associated strain field ...

AMER PHYSICAL SOC2023

Domain Imaging and Switching Dynamics in BaTiO3-Based Photonic Integrated Devices

Jacqueline Geler Kremer

Keeping up with our constantly connected lifestyle of instant messages and video streaming has its repercussions. Data centers have been gobbling up resources becoming a significant share of the energy used worldwide. To keep up with demand and curb the en ...

EPFL2023

Exploring negative capacitance and neuromorphic devices based on CMOS-compatible ferroelectric HfO2

Carlotta Gastaldi

Ferroelectric materials are explored for numerous applications thanks to their properties associated with electrically switchable spontaneous polarization. Perovskites are an established class of ferroelectrics used for sensors and actuators. However, they ...

EPFL2022

Actuation of piezoelectric structures with ferroelectric thin films having multiple elements

Paul Muralt

A method for driving piezoelectric elements of a micro-system. The piezoelectric elements comprising a ferroelectric thin film, and being configured to be part of any one or a combination of items of a list comprising: a cantilever, a bridge, a diaphragm, ...

2020

System and method for ground consolidation

Lyesse Laloui, Dimitrios Terzis, Patrick Gabriel Yihsiu-Ming Hicher

The present invention relates to a method for inducing ground consolidation. The method comprises providing a first chamber (7) in a first hole (3) in the ground (5), and a second chamber (7) in a second hole (3) in the ground (5), the first and second cha ...

2020

Nanowire Tunnel FET with Simultaneously Reduced Subthermionic Subthreshold Swing and Off-Current due to Negative Capacitance and Voltage Pinning Effects

Mihai Adrian Ionescu, Igor Stolichnov, Ali Saeidi, Teodor Rosca, Matteo Cavalieri

Nanowire tunnel field-effect transistors (TFETs) have been proposed as the most advanced one-dimensional (1D) devices that break the thermionic 60 mV/decade of the subthreshold swing (SS) of metal oxide semiconductor field-effect transistors (MOSFETs) by u ...

AMER CHEMICAL SOC2020

Electrical energy generated by silicone elastomers filled with nanospring- carbon- nanotubes

Frank Nüesch

Dielectric elastomer generators (DEGs) are flexible capacitors that convert mechanical into electrical energy. They rely on an external voltage source to charge the capacitor during each operation cycle. An alternative to this is an autonomous DEG which op ...

Royal Society of Chemistry2019

Modeling Dielectric Constant Variability in Aggregate Polymers from CV Measurements

Marco Mattavelli, Jean-Michel Sallese, Catherine Dehollain, Diego Ruben Barrettino

Recently a new technique based on capacitive sensing has been developed and used to estimate the amount of moisture in polymers by means of the deviation of the dielectric constant. This technique is expected to be used for in-line monitoring of aggregate ...

IEEE2019

Long-range symmetry breaking in embedded ferroelectrics

Dragan Damjanovic

The characteristic functionality of ferroelectric materials is due to the symmetry of their crystalline structure. As such, ferroelectrics lend themselves to design approaches that manipulate this structural symmetry by introducing extrinsic strain. Using ...

2018

Poleable Dielectric Elastomer Composites

Yee Song Ko

As part of the recent efforts on renewable energies, energy harvesting by exploiting environmental motions and vibrations to generate electricity is being enthusiastically developed as a novel kind of green energy source. Piezoelectric materials are a logi ...

EPFL2017

Piezoelectric softening by Nb substitution in (Ba,Pb)ZrO

Dragan Damjanovic, Nava Setter, Nicola Marzari, Alberto Biancoli, David Bahati

Donor doping is commonly applied for softening of the piezoelectric and dielectric properties and facilitation of polarization switching in the ubiquitous Pb(Zr,Ti)O-3 [PZT] ceramics. The origin of the donor-dopant effects is not entirely clear. (Pb,Ba)ZrO ...

Wiley-Blackwell2017

Manipulation of the Two-Dimensional States at Titanates Surfaces studied by ARPES

Stefan Peter Muff

The transition metal oxides are known for their versatile physical properties and are therefore an active field of research towards possible new functionalities and applications. This thesis focuses on the subgroup of titanates with perovskite structure th ...

EPFL2017

Does the real part contain all the physical information?

Olivier Martin

Polarisation charge formed on nanostructure surfaces upon optical excitation provides a useful tool to understand the underlying physics of plasmonic systems. Plasmonic simulations in the frequency domain typically calculate the polarisation charge as a co ...

Iop Publishing Ltd2016

What is a ferroelectric-a materials designer perspective

Nava Setter

Ferroelectrics are usually defined as polar materials that display polarisation hysteresis. This is a functional definition. A structural definition exists too, based solely on symmetry arguments. The structural definition, useful e.g. for design of new ma ...

Taylor & Francis Ltd2016

Thin-film-specific elastic effects in ferroelectric domain structures

Konstantin Shapovalov

An essential feature of ferroelectric thin films is the presence in them of domain structures. In order to efficiently implement ferroelectric films into potential new ferroelectrics-based devices, it is of high interest to understand the behaviour of doma ...

EPFL2016

Multipactor Analysis in Parallel-Plate Waveguides Loaded by a Single Dielectric Slab

Michael Mattes, Francisco Edén Sorolla Rosario, Apostolos Sounas

This paper studies the evolution of the multipactor discharge inside a parallel-plate waveguide partially loaded by a dielectric slab. The effect of static charges on the dielectric surface as well as of induced charges on the metallic plates are included. ...

2014

Upper bounds for flexoelectric coefficients in ferroelectrics

Alexander Tagantsev, Petr Yudin

Flexoelectric effect is the response of electric polarization to the mechanical strain gradient. At the nano-scale, where large strain gradients are expected, the flexoelectric effect becomes appreciable and may substitute piezoelectric effect in centrosym ...

American Institute of Physics2014

Polarisation charges and scattering behaviour of realistically rounded plasmonic nanostructures

Olivier Martin

We study the effect of realistically rounding nanorod antennae and gap antennae on their far field and near field properties. The simulations show that both scattering behaviour and polarisation charge distribution depend significantly on rounding. Roundin ...

Optical Society of America2013