Publications associées à Tailoring thermal conduction in anatase TiO2

Murunskite - a new class of functional material

The subject of the present work is discovery and in-depth characterization of a new class of functional materials. Tuning of the bond polarity and orbital occupation with a goal of establishing balance between localization and delocalization of electrons - ...

EPFL2023

III-V Nitride Semiconductors Deposited At Low Temperature For Photovoltaic Applications

Jonathan Emanuel Thomet

This thesis reports on the study and use of low temperature processes for the deposition of indium gallium nitride (InGaN) thin films in order to alleviate some of the present drawbacks of its monolitic deposition on silicon for photovoltaic applications. ...

EPFL2023

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

Crystallization and Organic Field-Effect Transistor Performance of a Hydrogen-Bonded Quaterthiophene

Philippe Bugnon, Rosario Scopelliti, Stéphane Suarez, Anne-Clémence Corminboeuf, Holger Frauenrath, Jan Gebers, Riccardo Petraglia, Piotr De Silva, Bilal Özen

Crystalline thin films of pi-conjugated molecules are relevant as the active layers in organic electronic devices. Therefore, materials with enhanced control over the supramolecular arrangement, crystallinity, and thin-film morphology are desirable. Herein ...

2020

Hydrogen-Bonded Small Molecules and Polymers in Organic Electronics

Bilal Özen

Organic semiconductors are important components for applications in different fields of technology, as their advantages include the possibility of low-temperature processing as well as low-cost, large-area manufacturing based on solution-based processes, c ...

EPFL2020

Electrochemical and morphological engineering of 2D materials for nanopore sensing

Martina Lihter

Nanopores are nanometer-sized holes that were initially proposed for DNA sequencing. Several years ago sequencing was made possible with biological nanopores. However, solid-state nanopores have plenty of advantages to offer compared to their biological co ...

EPFL2020

Crystal Phase Engineering in III-V Semiconductor Films: from Epitaxy to Devices

Philipp Staudinger

Crystal phase engineering is an exciting pathway to enhance the properties of conventional semiconductors. Metastable SiGe presents a direct band gap well suited for optical devices whereas wurtzite (WZ) phosphide alloys enable efficient light emission in ...

EPFL2020

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

Large-Scale Computational Screening of Molecular Organic Semiconductors Using Crystal Structure Prediction

Michele Ceriotti, Sandip De

Predictive computational methods have the potential to significantly accelerate the discovery of new materials with targeted properties by guiding the choice of candidate materials for synthesis. Recently, a planar pyrrole-based azaphenacene molecule (pyri ...

2018

Stretchable and Highly Bendable Thin Film Transistors Based on Atomically Thin Chemical Vapor Deposited Molybdenum Disulfide

Yen-Cheng Kung

Two-dimensional (2D) materials have received tremendous research attention recently, as they possess peculiar physical properties in their monolayer and few-layer forms, which further lead to novel applications. A wide range of 2D materials covers insulato ...

EPFL2018

Suppressing Nucleation in Metal–Organic Chemical Vapor Deposition of MoS2

Andras Kis, Davide Deiana, Dmitry Ovchinnikov, Dmitrii Unuchek, Hokwon Kim

Toward the large-area deposition of MoS2 layers, we employ metal–organic precursors of Mo and S for a facile and reproducible van der Waals epitaxy on c-plane sapphire. Exposing c-sapphire substrates to alkali metal halide salts such as KI or NaCl together ...

American Chemical Society (ACS)2017

Dynamics of Electronic and Ionic Charges in Cyanine Organic Semiconductor Devices

Sandra Christina Jenatsch

Organic semiconductor materials have been widely applied in optoelectronic devices to replace their inorganic counterparts and explore new fields of applications. Due to their high extinction coefficients, chemical tunability and solubility, cyanine dyes a ...

EPFL2017

Thermodynamics of the Segregation of a Kinetically Trapped Two-Dimensional Amorphous Metal-Organic Network

Klaus Kern, Claudius Morchutt

Surface-confined self-assembled molecular networks are commonly described as crystalline structures with short- and long-range order. Few exceptions to this trend are found in the literature reporting on amorphous and glassy networks and, discussing the or ...

Amer Chemical Soc2016

Arrays of Pentacene Single Crystals by Stencil Evaporation

Jürgen Brugger, Valentin Flauraud, Shenqi Xie

In order to realize high-performance organic thin-film transistors (TFT), two parameters of the organic semiconducting layer are desired: single crystallinity for high mobility and patterning for low off currents. High-quality single crystals can be fabric ...

2016

Pressure-tuned Transport Properties of Novel Iron-based Superconductors and Topological Insulators

Andrea Pisoni

The majority of interactions in solids strongly depend on the interatomic distances. The application of pressure changes the lattice parameters and modifies the electronic and the phononic energy spectra of a material avoiding some of the undesirable effec ...

EPFL2016

The Role of Transport Agents in MoS2 Single Crystals

Helmuth Berger, László Forró, Arnaud Magrez, Bálint Náfrádi, Arnaud Walter, Jacim Jacimovic, Andrea Pisoni

We report resistivity, thermoelectric power, and thermal conductivity of MoS2 single crystals prepared by the chemical vapor transport (CVT) method using I-2, Br-2, and TeCl4 as transport agents. The material presents low-lying donor and acceptor levels, w ...

Amer Chemical Soc2015

Optical properties of BiTeBr and BiTeCl

Helmuth Berger, Philippe Bugnon, Arnaud Magrez, Ana Akrap, Dirk Van der Marel

We present a comparative study of the optical properties-reflectance, transmission, and optical conductivity- and Raman spectra of two layered bismuth-tellurohalides BiTeBr and BiTeCl at 300 and 5 K, for light polarized in the a-b planes. Despite different ...

Amer Physical Soc2014

High-mobility organic thin-film transistors based on a small-molecule semiconductor deposited in vacuum and by solution shearing

Klaus Kern, Hagen Klauk

The small-molecule organic semiconductor 2,9-di-decyl-dinaphtho-[2,3-b: 2',3'-f]-thieno[3,2-b]-thiophene (C-10-DNTT) was used to fabricate bottom-gate, top-contact thin-film transistors (TFTs) in which the semiconductor layer was prepared either by vacuum ...

Elsevier Science Bv2013

Growth and Alignment of Thin Film Organic Single Crystals from Dewetting Patterns

Raffaele Mezzenga, Gaëtan Wicht, Thomas Geiger, Gian-Luca Bona, Roland Hany, Jakob Heier

Studying and understanding the conditions under which organic semiconductors can be engineered to form aligned single crystals in thin films is of primary importance owing to their unique orientation-dependent optoelectronic properties. Efforts to reach th ...

Amer Chemical Soc2013