Publications associées à Growth of single-crystalline KNbO3 nanostructures

Confirming the high pressure phase diagram of the Shastry-Sutherland model

A Muon Spin Rotation (mu+SR) study was conducted to investigate the magnetic properties of SrCu2(BO3)(2) (SCBO) as a function of temperature/pressure. Measurements in zero field and transverse field confirm the absence of long range magnetic order at high ...

IOP PUBLISHING LTD2023

Synthesis and Characterization of Functionalized Spacer Cations for the Incorporation in Layered Perovskites

Simon Nussbaum

Layered hybrid organic-inorganic perovskite (LHOIP) materials are an emerging class of semiconductors endorsed as a more stable alternative compared to the more widely investigated 3D hybrid organic-inorganic halide perovskites (HOIP). Consisting of altern ...

EPFL2023

Silica aerogel as rear reflector in silicon heterojunction solar cells for improved infrared response

Deniz Türkay

Silicon (Si), with its indirect bandgap, is a non-ideal absorber. Thus, various strategies to boost silicon solar cells' efficiency, including advanced texturing, multilayer anti-reflecting coating, and rear reflectors are utilized. Dielectrics, deposited ...

ELSEVIER2023

Decoding the Mechanisms of Phase Transitions from In Situ Microscopy Observations

Vasiliki Tileli, Reinis Ignatans

Analysis of the temperature- and stimulus-dependent imaging data toward elucidation of the physical transformations is an ubiquitous problem in multiple fields. Here, temperature-induced phase transition in BaTiO3 is explored using the machine learning ana ...

WILEY-V C H VERLAG GMBH2022

Molecular dynamics simulations of nucleation and phase transition in halide perovskites

Paramvir Ahlawat

Perovskite solar cells have emerged as the most promising cheaper photovoltaic technology. Besides solar cells, halide perovskites have a wide range of applications due to their remarkable optoelectronic properties. Starting from 3.8% in 2009, solar to the ...

EPFL2022

Intermediate phase engineering of halide perovskites for photovoltaics

Ulf Anders Hagfeldt, Zaiwei Wang, Wanchun Xiang, Jiahuan Zhang

Metal halide perovskites serving as one of the most promising photovoltaic materials are gaining considerable attention worldwide. For achieving high performance as well as long-term stability of the perovskite solar cells (PSCs), a good quality of perovsk ...

CELL PRESS2022

Molybdenum oxide as a case study for the diagnosis of carrier selective contacts in silicon heterojunction solar cells

Julie Amandine Dreon

Environmental challenges impose a rapid energy transition. The renewable power capacity is expected to increase by 50% in the next 5 years, and recent scenarios plan that photovoltaics (PV) will be leading the new energy sources. Combining high efficiencie ...

EPFL2022

Modeling and assessment of high-temperature photo-electrochemical devices

Ronald Ramiro Gutierrez Perez

In this thesis, the feasibility and performance of photo-driven electrochemical (PEC) devices working at elevated temperatures (T>700 K) is investigated and modeled. In such high-temperature PEC devices, a part of the solar spectrum is used for generating ...

EPFL2022

Temperature- and pressure-dependence of the hydrogen bond network in plastic ice VII

Livia Eleonora Bove Kado, Umbertoluca Ranieri, Maria Rescigno

We model, via classical molecular dynamics simulations, the plastic phase of ice VII across a wide range of the phase diagram of interest for planetary investigations. Although structural and dynamical properties of plastic ice VII are mostly independent o ...

AIP Publishing2022

Nanopillars Enabling III-V Integration on Si (100) and (111)

Lucas Güniat

The majority of current semiconductor technologies are built on Si (100), such as the CMOS technology, or conventional solar cell devices. III-V semiconductors offer great perspectives given their high carrier mobility and direct band gap. However their in ...

EPFL2021

A universal signature in the melting of metallic nanoparticles

Kevin Rossi

Predicting when phase changes occur in nanoparticles is fundamental for designing the next generation of devices suitable for catalysis, biomedicine, optics, chemical sensing and electronic circuits. The estimate of the temperature at which metallic nanopa ...

ROYAL SOC CHEMISTRY2021

Temperature‐dependent performance of silicon heterojunction solar cells with transition‐metal‐oxide‐based selective contacts

Mathieu Gérard Boccard, Julie Amandine Dreon

The temperature coefficient (TC) is an essential figure of merit to accurately evaluate solar cell performance at various operating temperatures and hence enabling the comparison between different cell technologies. Recently, solar cells that use passivati ...

2021

Compositional Engineering of Perovskite Light Absorbers for Enhanced Stability and Performance through 2D/3D Interfacing

Anwar Qasem M Alanazi

The semiconducting hybrid-organic inorganic halide perovskites have excellent optical and electronic properties that attract the interest of scientists and researchers. Perovskite solar cells have seen the most rising-rate in the chart of solar cell effici ...

EPFL2021

The Advantage of Nanowire Configuration in Band Structure Determination

Anna Fontcuberta i Morral, Elias Zsolt Stutz, Simon Robert Escobar Steinvall, Mirjana Dimitrievska

Earth-abundant and environmentally friendly semiconductors offer a promising path toward low-cost mass production of solar cells. A critical aspect in exploring new semiconducting materials and demonstrating their enhanced functionality consists in disenta ...

2021

Constraining the response factors of an extractive electrospray ionization mass spectrometer for near-molecular aerosol speciation

Yandong Tong, Julia Schmale, Imad El Haddad

Online characterization of aerosol composition at the near-molecular level is key to understanding chemical reaction mechanisms, kinetics, and sources under various atmospheric conditions. The recently developed extractive electrospray ionization time-of-f ...

2021

ZnSnxGe1-xN2 as electron-selective contact for silicon heterojunction solar cells

Christophe Ballif, Mathieu Gérard Boccard, Jonathan Emanuel Thomet, Luca Massimiliano Antognini, Vincent Philippe Paratte, Julie Amandine Dreon, Julien Hurni, Davi Marcelo Fébba

This work reports the electrical characterization of ZnSnxGe1-xN2 (ZTGN) layers deposited on glass by sputtering and further assesses for the first time the performance of SHJ solar cells featuring them as electron-selective contacts. Bandgap, conductivity ...

IEEE2021

Thermal coarsening of individual titanate nanowires and their assemblies: Surface vs. bulk diffusion

Luca Rossi, László Forró, Xavier Berdat, Massimo Spina, Endre Horvath, Laurent Syavoch Bernard, Sergiy Katrych

The thermal coarsening of titanate nanowires was investigated from room temperature to 1000 degrees C by AFM, SEM, XRD and Raman spectroscopy. Phase transformation kinetics and the external morphology were studied in two configurations: i) as individual an ...

2020

Structural properties of organometalic halide perovskite and their application in photodetectors

Anastasiia Glushkova

Hybrid organometallic halide perovskites have been intensively investigated in the past years as highly efficient light harvesters for various optoelectronic applications for both sensing and emitting light. However, many open questions remain regarding th ...

EPFL2020

Atomistic origins of the limited phase stability of Cs+-rich FAxCs(1-x)PbI3 mixtures

Michael Graetzel, Ursula Röthlisberger, Simone Meloni, Dominik Józef Kubicki, David Lyndon Emsley, Ariadni Boziki, Aditya Mishra

Mixed cation perovskites, [HC(NH2)2]xCs(1-x)PbI3, (FAxCs(1-x)PbI3) with x=0.8 achieve high solar cell power conversion efficiencies (PCEs) while exhibiting long-term stability under ambient conditions. In this work, we perform density functional theory (DF ...

2020

In situ control of the helical and skyrmion phases in Cu2OSeO3 using high-pressure helium gas up to 5 kbar

Arnaud Magrez, Henrik Moodysson Rønnow, Ivica Zivkovic, Jonathan White

We report a small-angle neutron scattering study of the helical and skyrmion lattice order in single-crystal Cu2OSeO3 under quasihydrostatic helium gas pressures up to 5 kbar. By using helium gas as the pressure-transmitting medium (PTM) we ensure pressure ...

AMER PHYSICAL SOC2020