Publications associées à Charge trapping effects in photovoltage measurements of (Ga,Mn)As

Photothermal spectroscopy on-chip sensor for the measurement of a PMMA film using a silicon nitride micro-ring resonator and an external cavity quantum cascade laser

Laser-based mid-infrared (mid-IR) photothermal spectroscopy (PTS) represents a selective, fast, and sensitive analytical technique. Recent developments in laser design permits the coverage of wider spectral regions in combination with higher power, enablin ...

Walter De Gruyter Gmbh2024

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

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

Pierre Christophe Lottigier

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

Laser-based manufacturing of freeform glass micro-optics through topological transformation

Samuel Youcef Benketaf

Glass has been the material of choice for making optical elements, in large part due to its intrinsic properties: a temperature-dependent viscosity, which enables shaping the material into a broad variety of functional and artistic glassware. Silica glass ...

EPFL2024

Method for operating a frequency agile tunable self-injection locking laser system and self-injection locking laser system

Tobias Kippenberg, Grigorii Likhachev, Anat Siddharth

The invention relates to a Method for operating a frequency agile tunable self-injection locking laser system being formed by a laser device coupled to at least one optical resonator, wherein a diode current of a laser diode of the laser device is controll ...

2023

Ultrafast tunable lasers using lithium niobate integrated photonics

Rui Ning Wang, Tobias Kippenberg, Junqiu Liu, Guanhao Huang, Mikhail Churaev, Anat Siddharth, Viacheslav Snigirev

Early works(1) and recent advances in thin-film lithium niobate (LiNbO3) on insulator have enabled low-loss photonic integrated circuits(2,3), modulators with improved half-wave voltage(4,5), electro-optic frequency combs(6) and on-chip electro-optic devic ...

NATURE PORTFOLIO2023

On the interaction of femtosecond laser pulses with layered dielectric materials

Ruben Ricca

Materials properties are strictly dependent on their microstructure. The internal symmetries and the disposition of the constituting atoms of a material, which depend on its crystallographic structure, greatly affect its response to mechanical, electromagn ...

EPFL2023

Charge Extraction and Recombination Dynamics of CdSe/CdTe Solar Cells Studied with Transient Photovoltage/Photocurrent Techniques

Mohammad Khaja Nazeeruddin, Iwan Zimmermann, Lei Chen

Significant advancements have been made in the development of high-performance cadmium telluride (CdTe)-based thin film solar cells. However, studies examining the transient excited-state charge dynamics, which determine the final steady-state device perfo ...

IEEE2023

All-glass miniature GHz repetition rate femtosecond laser cavity

Yves Bellouard, Antoine Maxime Delgoffe, Sargis Hakobyan, Saood Ibni Nazir

Free-space optics allows for design freedom and control, but miniaturization and manufacturability are limited. Here, we present a method for manufacturing complex miniaturized free-space optical systems that combines contactless femtosecond laser-activate ...

2023

Control of intermetallics in the interface in directed energy deposition of titanium on stainless steel 316L

Di Cui

Application of a single metal or alloy is often restricted by its properties from optimal combination of performance and cost. Therefore, there is a vast need of joining dissimilar metals for various applications in biomedical, aerospace, automobile and ma ...

EPFL2023

Single-frequency violet and blue laser emission from AlGaInN photonic integrated circuit chips

Tobias Kippenberg, Anat Siddharth

Chip-based, single-frequency and low phase-noise integrated photonic laser diodes emitting in the violet (412 nm) and blue (461 nm) regime are demonstrated. The GaN-based edge-emitting laser diodes were coupled to high-quality on-chip micro-resonators for ...

Optica Publishing Group2023

Potential-induced degradation in bifacial silicon heterojunction solar modules: Insights and mitigation strategies

Christophe Ballif, Quentin Thomas Jeangros, Alessandro Francesco Aldo Virtuani, Luca Gnocchi, Olatz Arriaga Arruti

Potential-induced degradation (PID) may be a serious concern in photovoltaic (PV) modules and plants, particularly when approaching high system voltages (1500+ V). Here, we investigate PID occurring in bifacial rear-emitter silicon heterojunction (SHJ) sol ...

Wiley2023

Cavitation induced by pulsed and continuous-wave fiber lasers in confinement

Christophe Moser, Jan Krizek

Bubbles generated with lasers in liquids under confinement have been investigated for their potential use as the driving mechanism for liquid micro-jets in various microfluidic devices, such as needle-free jet injectors. Here, we report on the study of bub ...

ELSEVIER SCIENCE INC2023

All-inorganic halide perovskites for air-processed "n-i-p" monolithic perovskite/organic hybrid tandem solar cells exceeding 23% efficiency

Mohammad Khaja Nazeeruddin

All-perovskite tandem solar cells recently surpassed 26% power conversion efficiency using a Sn(ii)-based halide perovskite rear subcell, which introduces several issues related to the chemical instability and the effectiveness of common, inexpensive inter ...

Royal Soc Chemistry2023

GeSn as next-generation material for short-wave infrared single-photon detection

Andrea Giunto

In recent years, the automotive industry has aspired to bring self-driving vehicles to the general public and light detection and ranging (LiDAR) sensors have emerged as the preferred solution for car vision systems. At present, LiDAR technologies employ e ...

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

Linear and nonlinear applications of miniaturized silicon nitride microresonators

Arslan Sajid Raja

Photonic integrated circuits (PICs) are the subject of massive interest due to the range of applications they can provide at a huge scale while building on well-established CMOS technologies. One of the critical parameters defining a technology's maturity ...

EPFL2023

X-ray qualification of hydrogenated amorphous silicon sensors on flexible substrate

Mikaël Martino, Sylvain Dunand, Nicolas Würsch, Luca Massimiliano Antognini, Matthew James Large

Hydrogenated amorphous silicon (a-Si:H) is a well known material for its radiation resistance and for the possibility of deposition on flexible substrates like Polyimide (PI), polyethylene terephthalate (PET) or polyethylene naphthalate (PEN). Due to the p ...

IEEE2023

Semiconductor-based device architectures in multimaterial fibers

William Nicolas Duncan Esposito

Semiconductor materials have given rise to today's digital technology and consumer electronics. Widespread adoption is closely linked to the ability to process and integrate them in devices at scale. Where flexibility and large surfaces are required, such ...

EPFL2023

Protection unit for wide bandgap power switching device and method for operating the wide bandgap power switching device

Drazen Dujic, Chengmin Li

The invention relates to a method for operating a power switching device, particularly a wide bandgap power switching device, in a power application, particularly in a converter, comprising the steps of:- checking (S2) a transient voltage of or related to ...

2023