Publications related to Space charge

Crossing the ballistic-ohmic transition via high energy electron irradiation

Philip Johannes Walter Moll, Matthias Carsten Putzke, Maja Deborah Bachmann

The delafossite metal PtCoO2 is among the highest-purity materials known, with low-temperature mean free path up to 5 mu m in the best as-grown single crystals. It exhibits a strongly faceted, nearly hexagonal Fermi surface. This property has profound cons ...

AMER PHYSICAL SOC2023

Phonons, electron-phonon coupling and charge transport in low-dimensional materials

Norma Rivano

Over the past few decades, nanostructures have garnered significant attention due to their potential for embodying new physical paradigms and delivering cutting-edge technological applications. Dimensionality strongly affects the vibrational, electron-phon ...

EPFL2023

Ultrafast Electron Microscopy of Nanoscale Charge Dynamics in Semiconductors

Fabrizio Carbone, Ivan Madan, Giovanni Maria Vanacore, Ido Kaminer, Simone Gargiulo, Francesco Barantani, Kangpeng Wang

The ultrafast dynamics of charge carriers in solids plays a pivotal role in emerging optoelectronics, photonics, energy harvesting, and quantum technology applications. However, the investigation and direct visualization of such nonequilibrium phenomena re ...

AMER CHEMICAL SOC2023

Charging and Electric Field Effects on Hydrogen Molecules Physisorbed on Graphene

Klaus Kern, Shai Mangel, Alessio Scavuzzo, Tobias Wollandt

Molecular hydrogen adsorbed on graphene was investigated by analyzing rotational excitation spectra obtained with a gate-tunable scanning tunneling microscope (STM). Through the shift of the rotational excitation energy, the tunability of physisorbed H2 on ...

AMER CHEMICAL SOC2023

Drift-Diffusion Simulations of Charge Transport and Trap Dynamics in Organic Semiconductor Materials

Camilla Arietta Vael-Garn

Polymeric semiconductors have gained significant attention in the field of organic electronics due to their unique properties and potential applications. Through their ability to transport charge carriers and to absorb or emit light, they have attracted mu ...

EPFL2023

Tailoring Organic/Inorganic Interface Trap States of Metal Oxide/Polyimide toward Improved Vacuum Surface Insulation

Chao Wang, Guang-Yu Sun, Haoxiang Zhao

High-voltage and high-power devices are indispensablein spacecraftfor outer space explorations, whose operations require aerospace materialswith adequate vacuum surface insulation performance. Despite persistentattempts to fabricate such materials, current ...

AMER CHEMICAL SOC2023

High-performance triboelectric nanogenerator via photon-generated carriers for green low-carbon system

Xin Chen

Enhancing the surface charge density and reducing the output impedance via innovative techniques are essential to accelerate the commercialization of triboelectric nanogenerators (TENGs). However, methods for increasing output performance have numerous lim ...

Elsevier2023

Scrutinizing thermally stimulated current transients originating from trapped charges in organic semiconductors: A drift-diffusion study

Frank Nüesch, Beat Ruhstaller

Thermally stimulated current (TSC) is a widely used technique to assess trap states and extract their density, energy, and capture rate using analytical expressions. In many cases, the latter are derived from physical models pertaining to inorganic semicon ...

AIP Publishing2022

Electron Trap Dynamics in Polymer Light-Emitting Diodes

Frank Nüesch, Roland Hany, Michael Bauer, Matthias Diethelm, Wei-Hsu Hu

Semiconducting polymers are being studied intensively for optoelectronic device applications, including solution-processed light-emitting diodes (PLEDs). Charge traps in polymers limit the charge transport and thus the PLED efficiency. It is firmly establi ...

WILEY-V C H VERLAG GMBH2022

Intrinsic Polarization Super Junctions: Design of Single and Multichannel GaN Structures

Elison de Nazareth Matioli, Luca Nela, Catherine Erine, Amirmohammad Miran Zadeh

Super junctions (SJs) have enabled unprecedented performance in Silicon power devices, which could be further improved by applying this concept to wide bandgap semiconductors like gallium nitride (GaN). Currently, polarization super junctions (PSJs) are th ...

2022

Vlasov simulation of the emissive plasma sheath with energy-dependent secondary emission coefficient and improved modeling for dielectric charging effects

Guang-Yu Sun

A one-dimensional Vlasov-Poisson simulation code is employed to investigate the plasma sheath considering electron-induced secondary electron emission (SEE) and backscattering. The SEE coefficient is commonly treated as constant in a range of plasma simula ...

FRONTIERS MEDIA SA2022

Gradient flow emulation using drift diffusion processes

Sanket Sanjay Diwale

The present invention concerns a method of emulating gradient flow for solving a given problem as a charge distribution in a device (1) comprising: first type charge carrier regions (5) interfacing a second type charge carrier region (11) thereby forming c ...

2021

Nanoscale Study of the Hole-Selective Passivating Contacts with High Thermal Budget Using C-AFM Tomography

Christophe Ballif, Franz-Josef Haug, Quentin Thomas Jeangros, Gizem Nogay, Philipp Friedrich Hermann Löper, Martin Ledinsky

We investigate hole-selective passivating contacts that consist of an interfacial layer of silicon oxide (SiOx) and a layer of boron-doped SiCx(p). The fabrication process of these contacts involves an annealing step at temperatures above 750 degrees C whi ...

AMER CHEMICAL SOC2021

Unveiling the role of dielectric trap states on capacitively coupled radio-frequency plasma discharge: dynamic charging behaviors

Guang-Yu Sun, Arnas Volcokas

The influence of charge trap states in the dielectric boundary material on capacitively coupled radio-frequency (RF) plasma discharge is investigated with theory and particle-in-cell/Monte Carlo collision simulation. It is found that the trap states of the ...

2021

Ionizing-Radiation Response and Low-Frequency Noise of 28-nm MOSFETs at Ultrahigh Doses

Christian Enz

Total ionizing dose (TID) mechanisms are investigated in 28-nm MOSFETs via dc static and low-frequency noise measurements. nMOSFETs and pMOSFETs are irradiated up to 1 Grad(SiO2) and annealed at high temperatures. TID sensitivity depends on the channel len ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2020

Long‐Lived Photocharges in Supramoelcular Polymers of Low‐Bandgap Chromophores

Andrzej Sienkiewicz, Holger Frauenrath, Daniel Görl, Regina Judith Hafner

Photoinduced charge separation in supramolecular aggregates of π‐conjugated molecules is a fundamental photophysical process, and a key criterion for the development of advanced organic electronics materials. Here, we report on the self‐assembly of novel l ...

2020

On-Chip Fully Integrated Field Emission Arrays for High-Voltage MEMS Applications

Vivek Subramanian

Vacuum-sealed fully integrated diode and triode field emission arrays based on Ti Spindt-type field emitters have been developed in a scalable, CMOS-compatible process directly on Si. Diode characterization in air demonstrates effective vacuum sealing and ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2020

Exciton and Carrier Dynamics in Two-Dimensional Perovskites

Jacques-Edouard Moser, Etienne Christophe Socie, Marine Eva Fedora Bouduban, Andrés Burgos Caminal

Two-dimensional Ruddlesden−Popper hybrid lead halide perovskites have become a major topic in perovskite optoelectronics. Here, we aim to unravel the ultrafast dynamics governing the evolution of charge carriers and excitons in these materials. Using a com ...

2020

Effect of the electrochemical characteristics of titanium on the adsorption kinetics of albumin

Anna Neus Igual Muñoz

An electrochemical quartz crystal microbalance (EQCM) was used to examine the electrochemical behaviour of pure titanium in phosphate buffered saline (PBS) and PBS-containing bovine serum albumin (BSA) solutions, and the associated adsorption characteristi ...

2019

Nonequilibrium exciton physics in hybrid lead-halide perovskites and anatase titanium dioxide

Tania Palmieri

The strength of the electron-hole interaction in bulk semiconductors is not only determined by the dielectric environment, but also depends on the presence of other quasiparticles - free charge carriers or phonons - that populate the system. In the former ...

EPFL2019