Publications associées à Impact of quantum confinement and quantum confined Stark effect on biexciton binding energy in GaN/AlGaN quantum wells

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

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

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

Strong coupling between a microwave photon and a singlet-triplet qubit

Jann Hinnerk Ungerer, Pasquale Scarlino

Combining superconducting resonators and quantum dots has triggered tremendous progress in quantum information, however, attempts at coupling a resonator to even charge parity spin qubits have resulted only in weak spin-photon coupling. Here, we integrate ...

Nature Portfolio2024

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

Persistent enhancement of exciton diffusivity in CsPbBr3 nanocrystal solids

Seryio Saris

In semiconductors, exciton or charge carrier diffusivity is typically described as an inherent material property. Here, we show that the transport of excitons among CsPbBr3 perovskite nanocrystals (NCs) depends markedly on how recently those NCs were occup ...

Amer Assoc Advancement Science2024

Ultra-high quantum coherent and scalable superconducting circuit optomechanics, from topological lattices to quantum storage

Amir Youssefi

Mechanical oscillators can exhibit modes with ultra-low energy dissipation and compact form factors due to the slow velocity of acoustic waves, and are already used in applications ranging from timing to wireless filters. Over the past decade, novel ways i ...

EPFL2024

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

Claudio Bruschini, Edoardo Charbon, Samuel Burri, Ivan Michel Antolovic, 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

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

Polariton lasing in AlGaN microring with GaN/AlGaN quantum wells

Jean-François Carlin, Nicolas Grandjean, Raphaël Butté

Microcavity polaritons are strongly interacting hybrid light-matter quasiparticles, which are promising for the development of novel light sources and active photonic devices. Here, we report polariton lasing in the UV spectral range in microring resonator ...

AIP Publishing2023

Towards semiconducting nano-engineered photocathodes for electron microscopy applications

Nicolas Tappy

The growing field of pulsed electron microscopy (PEM) currently suffers from technical challenges, many of which are related to the inefficiency of present pulsed emitters. In this research, we explore semiconductor photoemitters as a replacement of conven ...

EPFL2023

A squeezed mechanical oscillator with millisecond quantum decoherence

Tobias Kippenberg, Amir Youssefi, Mahdi Chegnizadeh, Shingo Kono

An enduring challenge in constructing mechanical-oscillator-based hybrid quantum systems is to ensure engineered coupling to an auxiliary degree of freedom and maintain good mechanical isolation from the environment, that is, low quantum decoherence, consi ...

NATURE PORTFOLIO2023

Synthesis and Characterization of Functionalized Spacer Cations for the Incorporation in Layered Perovskites

Simon Nussbaum

Layered hybrid organic-inorganic perovskite (LHOIP) materials are an emerging class of semiconductors endorsed as a more stable alternative compared to the more widely investigated 3D hybrid organic-inorganic halide perovskites (HOIP). Consisting of altern ...

EPFL2023

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

Indoor Self-Powered Perovskite Optoelectronics with Ultraflexible Monochromatic Light Source

Felix Thomas Eickemeyer, Tommaso Marcato, Hiroaki Jinno, Lukas Pfeifer

Self-powered skin optoelectronics fabricated on ultrathin polymer films is emerging as one of the most promising components for the next-generation Internet of Things (IoT) technology. However, a longstanding challenge is the device underperformance owing ...

Wiley-V C H Verlag Gmbh2023

Transcapacitances Modeling in ultra-thin gate-all-around junctionless nanowire FETs, including 2D quantum confinement

Farzan Jazaeri

In this work, we propose an analytical model for the intrinsic transcapacitances in ultra-thin gate-all-around junctionless nanowire field effect transistors in the presence of confined energy states of electrons. The validity of the developed model is con ...

PERGAMON-ELSEVIER SCIENCE LTD2023

Optoelectronics based on the spin-valley physics of 2D materials

Juan Francisco Gonzalez Marin

Two-dimensional (2D) materials are atomically thin crystals with exceptional mechanical, electrical and optical properties. Their unique characteristics originating from quantum confinement in the vertical dimension have attracted a strong interest for sci ...

EPFL2022

Deep defects in InGaN LEDs: modeling the impact on the electrical characteristics

Jean-François Carlin, Nicolas Grandjean, Camille Haller

Deep defects have a fundamental role in determining the electro-optical characteristics and in the efficiency of InGaN light-emitting diodes (LEDs). However, modeling their effect on the electrical characteristics of the LED is not straightforward. ...

SPIE-INT SOC OPTICAL ENGINEERING2022

Donor-Acceptor-Donor "Hot Exciton" Triads for High Reverse Intersystem Crossing in OLEDs

Anne-Clémence Corminboeuf, Sergio Vela Llausi, Maria Fumanal Quintana, Yanan Zhu

Hot exciton materials have the potential to improve the quantum efficiency of organic light-emitting diodes (OLEDs) by promoting high reversed intersystem crossing (hRISC) between a high-lying triplet (T-n, n >= 2) and a radiative singlet (S-m). In recent ...

WILEY-V C H VERLAG GMBH2022

Modeling the electrical characteristic of InGaN/GaN blue-violet LED structure under electrical stress

Jean-François Carlin, Nicolas Grandjean, Camille Haller

The role of deep defects and their physical origin in InGaN/GaN LED are still widely investigated and debated, in particular their impact on the electrical and optical characteristics and on the reliability of the device. In this paper we evaluate the elec ...

PERGAMON-ELSEVIER SCIENCE LTD2022