Publications associées à Rétroéclairage

Doping Engineering for PDP Optimization in SPADs Implemented in 55-nm BCD Process

Edoardo Charbon, Claudio Bruschini, Myung Jae Lee, Feng Liu

We introduce a new family of single-photon avalanche diodes (SPADs) with enhanced depletion regions in a 55-nm Bipolar-CMOS-DMOS (BCD) technology. We demonstrate how to systematically engineer doping profiles in the main junction and in deep p-well layers ...

Ieee-Inst Electrical Electronics Engineers Inc2024

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

Heralded Spectroscopy: a new single-particle probe for nanocrystal photophysics

Edoardo Charbon, Claudio Bruschini, Ivan Michel Antolovic, Samuel Burri, Arin Can Ülkü

Semiconductor nanocrystals feature multiply-excited states that display intriguing physics and significantly impact nanocrystal-based technologies. Fluorescence supplies a natural probe to investigate these states. Still, direct observation of multiexciton ...

SPIE2023

Resolving the Controversy in Biexciton Binding Energy of Cesium Lead Halide Perovskite Nanocrystals through Heralded Single-Particle Spectroscopy

Edoardo Charbon, Claudio Bruschini, Ivan Michel Antolovic, Samuel Burri, Arin Can Ülkü

Understanding exciton-exciton interaction in multiply excited nanocrystals is crucial to their utilization as functional materials. Yet, for lead halide perovskite nanocryst-als, which are promising candidates for nanocrystal-based technologies, numerous c ...

AMER CHEMICAL SOC2021

Toward Bright and Pure Single Photon Emitters at 300 K Based on GaN Quantum Dots on Silicon

Nicolas Grandjean, Raphaël Butté, Johann Nicolaï Stachurski, Gordon Jens Callsen, Sebastian Pascal Tamariz Kaufmann, Kanako Shojiki

Quantum dots (QDs) based on III-nitride semi-conductors are promising for single photon emission at noncryogenic temperatures due to their large exciton binding energies. Here, we demonstrate GaN QD single photon emitters operating at 300 K with g((2)) (0) ...

AMER CHEMICAL SOC2020

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

Highly spatially resolved mapping of the piezoelectric potentials in InGaN quantum well structures by off-axis electron holography

Victor Carle Adrien Boureau

The internal fields in 2.2nm thick InGaN quantum wells in a GaN LED structure have been investigated by using aberration-corrected off-axis electron holography with a spatial resolution of better than 1nm. To improve the spatial resolution, different types ...

2020

Room temperature single photon emission from planar GaN/AlN quantum dot samples grown by MBE

Nicolas Grandjean, Gordon Jens Callsen, Sebastian Pascal Tamariz Kaufmann

We present an overview on the growth and the optical properties of GaN quantum dots (QDs) embedded in planar AlN grown on the following three different types of substrates: single AlN crystal, AlN on sapphire, and AIN on Si(111). QD density control over th ...

IEEE2019

GaN Quantum Dots for Room Temperature Excitonic Physics

Sebastian Pascal Tamariz Kaufmann

Quantum dots (QDs) are the result of quantum confinement in the three spatial directions, as such they exhibit remarkable properties, of which the most important is perhaps the absence of a continuum of states. The allowed energetic levels are discrete, si ...

EPFL2019

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

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

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

InAs/InP quantum dot VECSEL emitting at 1.5 mu m

Elyahou Kapon, Grigore Suruceanu, Alexandru Mereuta, Andrei Caliman

A high-power InAs quantum dot (QD) vertical-external-cavity surface-emitting laser emitting at 1.5 mu m is reported. The active region employs 20 layers of high-density Stranski-Krastanow InAs quantum dots on an InP substrate. The QD density and emission w ...

AMER INST PHYSICS2019

InAlN underlaver for near ultraviolet InGaN based light emitting diodes

Nicolas Grandjean, Jean-François Carlin, Mauro Mosca, Camille Haller, Rolf Erni

We report on InAlN underlayer (UL) to improve the efficiency of near ultraviolet (NUV) light emitting diodes (LEDs). While InGaN UL is commonly used in high-efficiency blue LEDs it may absorb light for shorter wavelengths. InAlN lattice-matched to GaN exhi ...

2019

Density control of GaN quantum dots on AlN single crystal

Nicolas Grandjean, Gordon Jens Callsen, Sebastian Pascal Tamariz Kaufmann

Full control over the density and emission properties of GaN quantum dots (QDs) should be feasible, provided that the growth proceeds in the Stranski-Krastanov (SK) growth mode. In this work, we derive the phase diagram for GaN QD formation on AlN by NH3-m ...

2019

Thin-layer black phosphorous/GaAs heterojunction p-n diodes

Klaus Kern, Marko Burghard, Pascal Gehring

Owing to its high carrier mobility and thickness-tunable direct band gap, black phosphorous emerges as a promising component of optoelectronic devices. Here, we evaluate the device characteristics of p-n heterojunction diodes wherein thin black phosphorous ...

Amer Inst Physics2015

Integration of multiple site-controlled pyramidal quantum dot systems with photonic-crystal membrane cavities

Elyahou Kapon, Alok Rudra, Benjamin Dwir, Pascal Gallo, Alexey Lyasota, Clément William Tendaï Jarlov

We describe the fabrication, epitaxial growth and photoluminescence (PL) spectra of systems of site-controlled pyramidal quantum dots (QDs) integrated with photonic crystal (PhC) membrane cavities. The spectra of the individual QDs are characterized by sca ...

Elsevier Science Bv2015

Ultrafast spectroscopy of wide bandgap semiconductor nanostructures

Mehran Shahmohammadi

Group III-nitrides have been considered a promising choice for the realization of optoelectronic devices since 1970. Since the first demonstration of the high-brightness blue light-emitting diodes (LEDs) by Shuji Nakamura and coworkers, the fabrication of ...

EPFL2015

3D Gaze Estimation from Remote RGB-D Sensors

Kenneth Alberto Funes Mora

The development of systems able to retrieve and characterise the state of humans is important for many applications and fields of study. In particular, as a display of attention and interest, gaze is a fundamental cue in understanding people activities, be ...

EPFL2015

Synthesis of authenticable halftone images with non-luminescent halftones illuminated by an adjustable luminescent emissive layer

Roger Hersch, Julien Alexandre Andres

A method and computing system are proposed for producing an authenticable security device with two sides. The verso side is covered with an adjustable luminescent emissive layer formed by invisible luminescent ink halftones and possibly a UV absorbing prin ...

2014

Color Reproduction of Authenticable Luminescent Backlit Transmissive Color Images

Roger Hersch, Julien Alexandre Andres

We propose a method for creating authenticable color images under UV excitation backlight by printing an invisible luminescent white emissive ink layer on the verso side of a transmissive substrate and a classical cmy image on the recto side of the substra ...

Wiley-Blackwell2014

Quantum Dot Opto-Mechanics in a Fully Self-Assembled Nanowire

Anna Fontcuberta i Morral, Martin Heiss, Yannik Fontana, Eleonora Russo

We show that optically active quantum dots (QDs) embedded in MBE-grown GaAs/AlGaAs core-shell nanowires (NWs) are coupled to the NW mechanical motion. Oscillations of the NW modulate the QD emission energy in a broad range exceeding 14 meV. Furthermore, th ...

American Chemical Society2014