Publications associées à Optical characterization of fully programmable MEMS diffraction gratings

Publications associées (27)

Engineering Absorption for Foil Applications

Light matter interactions such as extinction, reflection, and transmission can be described by classical optics. Dur-ing the past decades, research focused on a novel resonant extinction type called plasmonics that allows for en-hancement of both types of ...

EPFL2022

Pitfalls in the spectral measurements of polarization-altering metasurfaces

Olivier Martin, Hsiang-Chu Wang

The optical characterization of metasurfaces and nanostructures that alter the polarization of light is tricky and can lead to unphysical results, such as reflectance beyond unity. We track the origin of such pitfalls to the response of some typical optica ...

Optica Publishing Group2022

Formation of High-Performance Multi-Cation Halide Perovskites Photovoltaics by delta-CsPbI3/delta-RbPbI3 Seed-Assisted Heterogeneous Nucleation

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Mounir Driss Mensi, Felix Thomas Eickemeyer, Bowen Yang, Linfeng Pan, Zaiwei Wang, Anurag Krishna, Essa Awadh R Alharbi, Thomas Paul Baumeler, Masaud Hassan S Almalki, Olivier Ouellette

The performance of perovskite solar cells is highly dependent on the fabrication method; thus, controlling the growth mechanism of perovskite crystals is a promising way towards increasing their efficiency and stability. Herein, a multi-cation halide compo ...

2021

Prototype mitre bends of the ex-vessel waveguide system for the ITER upper launcher: Thermal hydraulic simulations and experiments with off-center mm-wave beams

Timothy Goodman, René Chavan, Anastasia Xydou, Matteo Vagnoni, Humberto Torreblanca Quiroz

On ITER, long pulse gyrotrons are required as a power source for electron cyclotron heating (ECH) and current drive (CD). The microwaves are guided from the gyrotrons, which are placed far from the Tokamak, into the plasma by transmission lines (TLs) and a ...

Elsevier2021

Interfacial Effects in Hybrid Perovskite Solar Cells : Insights from First Principles Studies

Farzaneh Jahanbakhshi

Development of sustainable energy sources is among the most urgent needs of modern society. Solar energy technologies, and in particular, hybrid perovskite solar cells (HPSCs), have demonstrated hard-to-beat performances with large capacities for improveme ...

EPFL2021

Effect of illumination and applied potential on the electrochemical impedance spectra in triple cation (FA/MA/Cs) 3D and 2D/3D perovskite solar cells

Mohammad Khaja Nazeeruddin, Sanghyun Paek

Even though there has been numerous works performed based on electrochemical impedance spectroscopy (EIS) of perovskite solar cells (PSCs), however, many aspects of the obtained EI spectra are yet to be fully grasped. Moreover, the change of these spectra ...

ELSEVIER SCIENCE SA2021

Electromagnetic and mechanical analyses of the ITER electron cyclotron Upper launcher steering M4 mirrors for the vertical displacement event

Timothy Goodman, René Chavan, Avelino Mas Sanchez, Matteo Vagnoni, Phillip Miguel Santos Silva

The mm-wave power exiting the eight In-Vessel waveguides inside the ITER Electron Cyclotron Upper Launcher is reflected by three fixed mirror sets and finally aimed by two independent steering mirrors to specific plasma locations. A design solution for bot ...

2020

Surface-based luminescence measurement substrate

Nicolas Maxime André Descharmes, Raphaël Barbey

Surface-based measurement substrate including: • - at least one optical cavity layer (7); • - a first optical mirror (9) and a second optical mirror (11), the first and second optical mirrors enclosing the optical cavity layer and defining an optical cavit ...

2020

Intermediate Phase Enhances Inorganic Perovskite and Metal Oxide Interface for Efficient Photovoltaics

Michael Graetzel, Ulf Anders Hagfeldt, David Lyndon Emsley, Wolfgang Richard Tress, Dominik Józef Kubicki, Yuhang Liu, Zaiwei Wang, Aditya Mishra, Brian Irving Carlsen, Claudia Esther Avalos, Haizhou Lu, Anand Agarwalla

Interfacial modification is crucial to fully develop the potential of semiconductor devices, including the revolutionary halide perovskite-based optoelectronics, such as photovoltaics, light-emitting diodes, and photodetectors. The all-inorganic halide per ...

CELL PRESS2020

A hybrid niobium-based oxide with bio-based porous carbon as an efficient electrocatalyst in photovoltaics: a general strategy for understanding the catalytic mechanism

Ulf Anders Hagfeldt, Ziqi Wang, Cheng Wang

Developing a high-performance catalyst and establishing a catalytic mechanism for understanding the catalytic activity are crucial to new generation photovoltaic technology. In this work, we present a feasible and general route to synthesize a bio-based po ...

Royal Society of Chemistry2019

Large Hybrid High Precision MEMS Mirrors

Dara Zaman Bayat

This thesis presents the design and microfabrication technology of a tip-tilt, 2 degree of freedom "mirror system" made out of Silicon On Insulator (SOI) wafers with two movable mirrors that have diameter of 10 mm. The system was intended for precise beam ...

EPFL2011

Photoinitiator-free multi-photon fabrication of compact optical waveguides in polydimethylsiloxane

Demetri Psaltis, Christophe Moser, Ye Pu, Giulia Panusa, Jieping Wang

Compact, low loss flexible optical waveguides are crucial in optofluidic and microfluidic devices for a dense integration of optical functionalities. We demonstrate the fabrication of compact optical waveguides in polydimethylsiloxane through multiphoton l ...

2019

Solution-Processed Low-Bandgap CuIn(S,Se)(2) Absorbers for High-Efficiency Single-Junction and Monolithic Chalcopyrite-Perovskite Tandem Solar Cells

Alexander Roland Uhl

A novel molecular-ink deposition route based on thiourea and N,N-dimethylformamide (DMF) that results in a certified solar cell efficiency world record for non-vacuum deposited CuIn(S,Se)(2) (CIS) absorbers and non-vacuum deposited absorbers with a bandgap ...

WILEY-V C H VERLAG GMBH2018

Diagnostic mirrors for ITER: A material choice and the impact of erosion and deposition on their performance

Richard Pitts

Metal mirrors will be implemented in about half of the ITER diagnostics. Mirrors in ITER will have to withstand radiation loads, erosion by charge-exchange neutrals, deposition of impurities, particle implantation and neutron irradiation. It is believed th ...

2007

Insights into photovoltaic properties of ternary organic solar cells from phase diagrams

Jakob Heier, Philippe Schwaller, Surendra Babu Anantharaman

The efficiency of ternary organic solar cells relies on the spontaneous establishment of a nanostructured network of donor and acceptor phases during film formation. A fundamental understanding of phase composition and arrangement and correlations to photo ...

2018

TCV mirrors cleaned by plasma

Stefano Coda

Metallic mirrors exposed in TCV tokamak were cleaned by plasma in laboratory. A gold (Au) mirror was deposited with 185-285 nm of amorphous carbon (aC:D) film coming from the carbon tiles of TCV. Another molybdenum (Mo) mirror had a thicker deposit due to ...

Elsevier2017

Multiple scattering in optical coherence tomography. I. Investigation and modeling

Theo Lasser, Marcel Leutenegger, Stéphane Bourquin, Boris Clément Karamata, Markus Laubscher

We present a new model of optical coherence tomography (OCT) taking into account multiple scattering. A theoretical analysis and experimental investigation reveals that in OCT, despite multiple scattering, the field backscattered from the sample is general ...

2005

Back-Propagating the Light of Field Stars to Probe Telescope Mirrors Aberrations

Michaël Unser, Frédéric Courbin, Ferréol Arnaud Marie Soulez

We propose a wavefront-based method to estimate the PSF over the whole field of view. This method estimate the aberrations of all the mirrors of the telescope using only field stars. In this proof of concept paper, we described the method and present some ...

SPIE2016

Plasma cleaning of beryllium coated mirrors

Cleaning systems of metallic first mirrors are needed in more than 20 optical diagnostic systems from ITER to avoid reflectivity losses. Currently, plasma sputtering is considered as one of the most promising techniques to remove deposits coming from the m ...

Iop Publishing Ltd2016

Dynamics of Photocarrier Separation in MAPbI3 Perovskite Multigrain Films under a Quasistatic Electric Field

Jacques-Edouard Moser, Joël Teuscher, Arun Aby Paraecattil, Jelissa Risse

Applying time-resolved electroabsorption spectroscopy for the first time to methylammonium lead triiodide perovskite (MAPbI3) thin films under reverse bias, we monitored optically the ultrafast evolution of the local counter-electric field produced by the ...

American Chemical Society2016