Publications related to Tunable Polaronic Conduction in Anatase TiO2

Shortwave Infrared-Sensitive, Narrowband Organic Upconversion Devices with a Gain

Sensing and imaging of light in the shortwave infrared (SWIR) range is increasingly used in various fields, including bio-imaging, remote sensing, and semiconductor process control. SWIR-sensitive organic photodetectors (OPDs) are promising because organic ...

EPFL2024

Controlling On-Surface Photoactivity: The Impact of π-Conjugation in Anhydride-Functionalized Molecules on a Semiconductor Surface

Karl-Heinz Ernst, Christian Wäckerlin

On-surface synthesis has become a prominent method for growing low-dimensional carbon-based nanomaterials on metal surfaces. However, the necessity of decoupling organic nanostructures from metal substrates to exploit their properties requires either trans ...

Wiley-VCH Verlag GmbH2024

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

Momentum-Space Imaging of Ultra-Thin Electron Liquids in δ-Doped Silicon

Nicolò D'Anna, Gabriel Aeppli

Two-dimensional dopant layers (δ-layers) in semiconductors provide the high-mobility electron liquids (2DELs) needed for nanoscale quantum-electronic devices. Key parameters such as carrier densities, effective masses, and confinement thicknesses for 2DELs ...

WILEY2023

Engineering of PEM-PEC photocathodes for solar-driven hydrogen production

Marina Caroline Michèle Caretti

Earth has always been in perpetual evolution, but today we must face its rapid change due to human activity. The intensification of industrial activities and transportation to support our modern lifestyles are the main causes of climate change and the adve ...

EPFL2022

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

Crystalline Order in Compound Semiconductors in Nanoscale Structures and Thin Films

Mahdi Zamani

Semiconductors materials and devices are essential building blocks for many of the technologies deeply embedded in modern life. Improving the performance of semiconductor devices requires a deeper understanding of the fundamental mechanisms controlling the ...

EPFL2021

Interaction of Confined Polaritons in Microcavity Structures

Morteza Navadeh Toupchi

A polariton is a quasiparticle formed from the coupling of a confined photon in a cavity to electronic excitation, like exciton in a semiconductor. This dissertation reports on series of experiments in confined polariton interaction by design, fabrication, ...

EPFL2021

Novel Interfacial Characterization and Surface Engineering in Semiconductor Electrodes for Optimized Solar Fuel Production

Yongpeng Liu

Harvesting sunlight, the ultimate renewable power source, in a cost-effective way has been long recognized as a necessary route to meet the global energy challenges. Solar energy can be transformed into electricity by means of photovoltaic devices to suppl ...

EPFL2021

Benzodithiophene‐Based Spacers for Layered and Quasi‐Layered Lead Halide Perovskite Solar Cells

Mounir Driss Mensi, Jun Ho Yum, Kevin Sivula, Nestor Guijarro Carratala, Luc Emile Monnier, Liang Yao, Barbara Alexandra Primera Darwich, Han-Hee Cho

Incorporating extended pi-conjugated organic cations in layered lead halide perovskites is a recent trend promising to merge the fields of organic semiconductors and lead halide perovskites. Herein, we integrate benzodithiophene (BDT) into Ruddlesden–Poppe ...

2021

Rational Design of Hole Transport Materials: Tools and Structure-Packing-Property Relationships

Kun-Han Lin

The growing demand for low-cost, large-scale and flexible electronics has led to a boost in research on organic semiconductors (OSC). Understanding structure-packing-property relationships (SPPR) and the role of molecular building blocks in charge transpor ...

EPFL2020

Ultra-broadband time-resolved THz spectroscopy of perovskites and nanomaterials

Andrés Burgos Caminal

The fundamental study of charge carrier dynamics has been shown to be of great interest for optoelectronics, paving the way forward for future developments. Often, some of the key processes that determine the photophysics of a material occur on very short ...

EPFL2020

Hot-Hole versus Hot-Electron Transport at Cu/GaN Heterojunction Interfaces

Giulia Tagliabue

Among all plasmonic metals, copper (Cu) has the greatest potential for realizing optoelectronic and photochemical hot-carrier devices, thanks to its CMOS compatibility and outstanding catalytic properties. Yet, relative to gold (Au) or silver (Ag), Cu has ...

AMER CHEMICAL SOC2020

High-Performance III-V MOSFETs and Tunnel-FETs Integrated on Silicon

Clarissa Convertino

Silicon transistor scaling is approaching its end and a transition to novel materials and device concepts is more than ever essential. High-mobility compound semiconductors are considered promising candidates to replace silicon, targeting low-power logic a ...

EPFL2020

Enhanced Electron-Phonon Interaction in Multivalley Materials

Helmuth Berger, Nicola Marzari, Evgeniy Ponomarev, Marco Gibertini, Thibault Daniel Pierre Sohier

We report a combined experimental and theoretical investigation that reveals a new mechanism responsible for the enhancement of electron-phonon coupling in doped semiconductors in which multiple inequivalent valleys are simultaneously populated. Using Rama ...

American Physical Society2019

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

Valley-Engineering Mobilities in Two-Dimensional Materials

Nicola Marzari, Giovanni Pizzi, Marco Gibertini, Thibault Daniel Pierre Sohier, Davide Campi

Two-dimensional materials are emerging as a promising platform for ultrathin channels in field-effect transistors. To this aim, novel high-mobility semiconductors need to be found or engineered. Although extrinsic mechanisms can in general be minimized by ...

AMER CHEMICAL SOC2019

Multiple morphologies and functionality of nanowires made from earth-abundant zinc phosphide

Thomas La Grange, Anna Fontcuberta i Morral, Elias Zsolt Stutz, Jean-Baptiste Leran, Nicolas Tappy, Reza Zamani, Mahdi Zamani, Simon Robert Escobar Steinvall, Rajrupa Paul

Semiconductors made of earth-abundant elements, such as zinc phosphide, have the potential to substitute less abundant, highly functional compound semiconductors such as InAs or InP. Compound semiconductors in the form of nanowires could revolutionise appl ...

2020

Alignment of energy levels in amorphous oxides and at semiconductor-water interfaces

Zhendong Guo

We conduct a detailed investigation of defects in two representative amorphous oxides: amorphous Al2O3 (am-Al2O3) and TiO2 (am-TiO2), by combining ab initio molecular dynamics (MD) simulations and hybrid functional calculations. Our results indicate that o ...

EPFL2019

Defect Formation Energies of Interstitial C, Si, and Ge Impurities in beta-Ga2O3

Alfredo Pasquarello, Assil Bouzid

Formation energies of C, Si, and Ge defects in beta-Ga2O3 are studied through hybrid functional calculations. The interstitial defects of these elements generally occur at higher energies than their substitutional counterparts, but are more stable at low F ...

WILEY-V C H VERLAG GMBH2019