Publications associées à High-power modular LED-based illumination systems for mask-aligner lithography

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

Printed ecoresorbable temperature sensors for environmental monitoring

Danick Briand, James Alec Pierce Bourely, Nicolas Francis Fumeaux, Melissa Kossairi

Electronic waste has become a pressing issue, necessitating sustainable solutions for the disposal of electronic devices. While the development of environmentally degradable electronics has gained attention, the fabrication of stable and performant sensors ...

2023

First developments towards producing inductive magnetic sensors using state-of-the-art photolithography techniques

Duccio Testa, Ambrine Douhane, Marcus Cemes

Inductive magnetic sensors are needed for tokamak operation to provide the low-frequency (LF) measurements leading to the equilibrium reconstruction and to monitor the higher frequency (HF) instabilities; the HF magnetic sensors are often also used as a ba ...

2023

Laser-Induced Forward Transfer of Functional Microdevices

Zhiwei Yang

Laser-induced forward transfer (LIFT) technique is an emerging micro additive manufacturing (AM) technique that has been widely used to print a variety of materials. Distinguished from other nozzle-based AM techniques, LIFT operates without the existence o ...

EPFL2023

The nanoscale impact of individual nonradiative point defects on InGaN/GaN quantum wells

Thomas Fjord Kjaersgaard Weatherley

Today's world depends on optoelectronic devices: light-emitting diodes illuminate our houses and backlight the displays on our gadgets, while laser diodes underpin fibre-optic communication. Such optoelectronic devices rely on crystalline semiconductor het ...

EPFL2023

Photochemical Alkynylations with Hypervalent Iodine Reagents

Stephanie Grace Elizabeth Amos

Over the past twenty years, photochemical transformations have gained in importance in organic chemistry. Indeed, the development of photocatalysts has allowed the use of visible light as an energy source for chemical transformations. More specifically, ph ...

EPFL2022

Separation and Recycling Potential of Rare Earth Elements from Energy Systems: Feed and Economic Viability Review

Christian Ludwig, Rudolf Paul Wilhelm Jozef Struis, Viktoria Paetzel, Ajay Bhagwan Patil

This review explores the potential of separating and recycling rare earth elements (REEs) from different energy conversion systems, such as wind turbines, electric vehicles batteries, or lighting devices. The REEs include 17 elements (with global productio ...

2022

Room-temperature electrical control of polarization and emission angle in a cavity-integrated 2D pulsed LED

Andras Kis, Dmitrii Unuchek, Juan Francisco Gonzalez Marin, Fedele Tagarelli, Cheol Yeon Cheon, Zhe Sun

Devices based on two-dimensional (2D) semiconductors hold promise for the realization of compact and versatile on-chip interconnects between electrical and optical signals. Although light emitting diodes (LEDs) are fundamental building blocks for integrate ...

Nature Research2022

Fabrication and applications of AuAg alloy metasurfaces and hybrid metal dielectric nanoantennas

Debdatta Ray

The most prevalent materials used in the field of plasmonics are Au and Ag. However, for the past few years, the plasmonic community has also been looking for alternative materials that have lower losses than Au and higher stability than Ag. This thesis is ...

EPFL2021

FABRICATION AND ANALYSIS OF THIN FILM LITHUM NIOBATE RESONATORS FOR 5GHz FREQUENCY AND LARGE k(t)(2) APPLICATIONS

Victor Plessky, Luis Guillermo Villanueva Torrijo, Seniz Esra Küçük, Soumya Yandrapalli

This work presents the fabrication and analysis of suspended thin film Lithium Niobate resonators. The yield of the new fabrication process presented below is >90% showing devices with high k(t)(2) of 28% resonators at 5GHz, making them suitable for high f ...

IEEE2021

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

Resonant Band-Edge Emissive States in Strongly Confined CsPbBr3 Perovskite Nanoplatelets

Jacques-Edouard Moser, Etienne Christophe Socie, Aaron Tomas Terpstra, Brener Rodrigo De Carvalho Vale

Strongly confined, fully inorganic cesium lead halide perovskite nanocrystals are of great promise for light-emitting devices in the blue spectral range owing to their high photoluminescence quantum yields. A combination of broadband fluorescence up-conver ...

2021

Femtosecond laser-based optomechanical processes for permanent and high-precision fine alignment of optical systems

Saood Ibni Nazir

Miniaturization has been at the forefront of scientific research in the past decade covering diverse areas such as electronics, mechanics, and optics. While 'small is beautiful' may be a vast generalization, the true benefits of miniaturization are especia ...

EPFL2021

Multi-User Precoder Designs for RGB Visible Light Communication Systems

Roser Vinals Terres

In this paper, we design linear precoders for the downlink of a visible light communication (VLC) system that simultaneously serves multiple users. Instead of using phosphor-coated white light-emitting diodes (PWLEDs), we focus on Red-Green-Blue light-emit ...

2020

Routes for Efficiency Enhancement in Fluorescent TADF Exciplex Host OLEDs Gained from an Electro-Optical Device Model

Frank Nüesch, Beat Ruhstaller, Markus Regnat

Fluorescence-based organic light-emitting diodes (OLEDs) using thermally activated delayed fluorescence (TADF) have increasingly attracted attention in research and industry. One method to implement TADF is based on an emitter layer composed of an exciplex ...

WILEY2020

Grayscale e-beam lithography: Effects of a delayed development for well-controlled 3D patterning

Henning Paul-Julius Stahlberg

Grayscale electron beam lithography (g-EBL) is a fabrication technique that allows for tunable control of resist topography. In most cases, the height of the structures is in the submicron regime. Here, we present an extensive experimental characterization ...

2020

Progress in Violet Light-Emitting Diodes Based on ZnO/GaN Heterojunction

Eric Feltin, Mauro Mosca

Progress in light-emitting diodes (LEDs) based on ZnO/GaN heterojunctions has run into several obstacles during the last twenty years. While both the energy bandgap and lattice parameter of the two semiconductors are favorable to the development of such de ...

MDPI2020

Single crystal diamond gain mirrors for high performance vertical external cavity surface emitting lasers

Niels Quack, Grigore Suruceanu, Alexandru Mereuta, Andrei Caliman, Pascal Gallo, Gergely Huszka, Mehdi Naamoun

We report on the design, fabrication and optical performance of gain mirrors in single crystal diamond substrates for vertical external cavity surface emitting lasers (VECSELs). VECSELs have gained attention recently due to their potential for high emissio ...

2020

Spatial coherence properties of an LED-based illumination system for mask-aligner lithography

Hans Peter Herzig, Wilfried Noell, Toralf Scharf, Johana Bernasconi, Raoul Kirner

A high-power LED-based illumination system has been developed as a replacement for the mercury arc lamps used in mask-aligner lithography. LEDs are arranged in a grid array and placed in the entrance aperture of individual reflectors. Those reflectors decr ...

SPIE2019

On Advanced Large-Field Photolithography

Raoul Kirner

The information age we live in today relies on highly integrated devices. They are fabricated with the help of photolithography, the patterning technique at the heart of their production. With the continuous demand for higher integration density to achieve ...

EPFL2019