Publications associées à Photonic contacting of gas-liquid phases in a falling film microreactor for continuous-flow photochemical catalysis with visible light

III-N blue-emitting epi-structures with high densities of dislocations: Fundamental mechanisms for efficiency improvement and applications

Since the dawn of humanity, human beings seeked to light their surroundings for their well-being, security and development. The efficiency of ancient lighting devices, e.g. oil lamps or candles, was in the order of 0.03-0.04% and jumped to 0.4-0.6% with th ...

EPFL2024

Organic matters, but inorganic matters too: column examination of elevated mercury sorption on low organic matter aquifer material using concentrations and stable isotope ratios

Lorenz Schwab

Sorption of mercury (Hg) in soils is suggested to be predominantly associated with organic matter (OM). However, there is a growing collection of research that suggests that clay minerals and oxides are also important solid phases for the sorption of solu ...

2024

Study of growth-induced point defects and their impact on InGaN-based optoelectronic devices

Yao Chen

GaN exhibits a decomposition tendency for temperatures far below its melting point and common growth temperatures used in metal-organic vapour phase epitaxy (MOVPE).This characteristic is known to be a major obstacle for realising GaN bulk substrate. There ...

EPFL2024

Investigation of room-temperature single-photon emitters in GaN-based materials and GaN/AlN quantum dots

Johann Nicolaï Stachurski

Over the past decade, quantum photonics platforms aiming at harnessing the fundamental properties of single particles, such as quantum superposition and quantum entanglement, have flourished. In this context, single-photon emitters capable of operating at ...

EPFL2024

Computational Studies on the Stability of Organic-Inorganic Hybrid Halide Lead Perovskites

Mathias Dankl

Perovskite-based solar cells are currently the most rapidly advancing photovoltaic technology but concerns about their long-term stability are still impeding full-scale commercialization. This thesis provides computational insights into some of the stabili ...

EPFL2024

Frustrated magnets in the limit of infinite dimensions: Dynamics and disorder-free glass transition

Achille Mauri

We study the statistical mechanics and the equilibrium dynamics of a system of classical Heisenberg spins with frustrated interactions on a d -dimensional simple hypercubic lattice, in the limit of infinite dimensionality d -> infinity . In the analysis we ...

Amer Physical Soc2024

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

Wei-Hsu Hu

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

Investigating Non-equilibrium Physics in Wide Bandgap Semiconductors and Quantum Materials via Ultrafast Spectroscopy

Hui-Yuan Chen

This thesis uses femtosecond laser spectroscopy in studying strong correlation in condensed matters that are pertinent to future technology: a wide bandgap perovskite and a quantum material, with the employment of ultrafast time-resolved spectroscopy in th ...

EPFL2024

Vapor compression and energy dissipation in a collapsing laser-induced bubble

Mohamed Farhat, Danail Obreschkow, Armand Baptiste Sieber, Davide Bernardo Preso

The composition of the gaseous phase of cavitation bubbles and its role on the collapse remains to date poorly understood. In this work, experiments of single cavitation bubbles in aqueous ammonia serve as a novel approach to investigate the effect of the ...

Aip Publishing2024

Field-controlled multicritical behavior and emergent universality in fully frustrated quantum magnets

Bruce Normand

Phase transitions in condensed matter are a source of exotic emergent properties. We study the fully frustrated bilayer Heisenberg antiferromagnet to demonstrate that an applied magnetic field creates a previously unknown emergent criticality. The quantum ...

Nature Portfolio2024

Plasmonic Nanostructures for Photocatalysis: Material, Photonic and Electronic Effects

Fateme Kiani Shahvandi

Plasmonic photochemistry has a large potential to replace energy-intensive chemical processes with low-temperature, low-pressure light-driven chemical reactions. Plasmonic nanostructures have emerged as promising photocatalysts with exceptional and tunable ...

EPFL2024

Local vs. cooperative: Unraveling glass transition mechanisms with SEER

Matthieu Wyart, Wencheng Ji

Which phenomenon slows down the dynamics in supercooled liquids and turns them into glasses is a long-standing question of condensed matter. Most popular theories posit that as the temperature decreases, many events must occur in a coordinated fashion on a ...

National Academy of Sciences2024

Mixed ionic-electronic conduction in Ruddlesden-Popper and Dion-Jacobson layered hybrid perovskites with aromatic organic spacers

Michael Graetzel, Davide Moia, Joachim Maier, Jovana Milic, Algirdas Ducinskas, Mina Jung

The understanding of mixed ionic-electronic conductivity in hybrid perovskites has enabled major advances in the development of optoelectronic devices based on this class of materials. While recent investigations revealed the potential of using dimensional ...

Royal Society of Chemistry2024

A thermotropic liquid crystal enables efficient and stable perovskite solar modules

Mohammad Khaja Nazeeruddin, Bin Ding, Jian Xu, Yong Ding, Cheng Liu

Perovskite solar cells have seen impressive progress in performance and stability, yet maintaining efficiency while scaling area remains a challenge. Here we find that additives commonly used to passivate large-area perovskite films often co-precipitate du ...

Nature Portfolio2024

Mott physics in the multiflavored age

Frédéric Mila

The multiflavor Mott insulators, whose local Hilbert space consists of multiple degrees of freedom, occur widely in both quantum materials and ultracold atom systems. This Comment recommends the review article by Chen and Wu that is, to the author's knowle ...

Nature Portfolio2024

Stick-slip-to-stick transition of liquid oscillations in a U-shaped tube

François Gallaire, Alessandro Bongarzone

The nonlinear decay of oscillations of a liquid column in a U-shaped tube is investigated within the theoretical framework of the projection method formalized by Bongarzone et al. [Chaos 31, 123124 (2021)]. Starting from the full hydrodynamic system supple ...

Amer Physical Soc2024

Enhanced performance of perovskite solar cell via up-conversion YLiF4:Yb, Er nanoparticles

Mounir Driss Mensi, Anwar Qasem M Alanazi, Masaud Hassan S Almalki

We report a simple and effective method for producing lanthanide ion-doped lithium-fluoride-based nanocrystals (YLiF4). We utilized those nanoparticles for up-conversion in fabricated perovskite solar cells. The obtained results shows that the up-conversio ...

Elsevier2024

Tomographic microscopy of functionally graded polymer-derived SiCN ceramics with tunable gradients

Jürgen Brugger, Lorenz Hagelüken

Polymer-derived ceramics (PDCs) are a very attractive class of materials due to their excellent properties such as resistance to high temperatures and harsh environments, adjustability of mechanical and functional behavior, and compatibility with a broad r ...

Elsevier Sci Ltd2024

Microstructural and electrical characterization of high temperature passivating contacts for silicon solar cells

Sofia Libraro

Recombination at metal/semiconductor interfaces represents the main limitation in mainstream c-Si solar cells, primarily based on the passivated emitter and rear cell (PERC) concept. Full-area passivating contacts based on SiOx/poly-Si stacks are a candida ...

EPFL2024

Hybrid organic/metal-oxide shells on semiconductor nanocrystals via colloidal atomic layer deposition

Ona Segura Lecina

The escalating energy demand and the imperative necessity to reduce the carbon footprint require transformative approaches to energy conversion. Materials chemistry plays a pivotal role in addressing these global challenges by developing novel materials fo ...

EPFL2024