Recherche

Afficher tous les résultats pour

Accueil

Personne

Gwénolé Jean Jacopin

Cette personne a quitté l’EPFL

À propos
Confidentialité
Mentions légales

Graph Chatbot

Publications associées (31)

Page 1 sur 2

Nanometer-scale monitoring of quantum-confined Stark effect and emission efficiency droop in multiple GaN/AlN quantum disks in nanowires

Gwénolé Jean Jacopin

We report on a detailed study of the intensity dependent optical properties of individual GaN/AlN quantum disks (QDisks) embedded into GaN nanowires (NW). The structural and optical properties of the QDisks were probed by high spatial resolution cathodolum ...

Amer Physical Soc2016

Insights about the Absence of Rb Cation from the 3D Perovskite Lattice: Effect on the Structural, Morphological, and Photophysical Properties and Photovoltaic Performance

Silvia Binet, Michael Graetzel, Shaik Mohammed Zakeeruddin, Mohammad Ibrahim Dar, Neha Arora, Gwénolé Jean Jacopin, Ryusuke Uchida

Efficiencies >20% are obtained from the perovskite solar cells (PSCs) employing Cs+ and Rb+ based perovskite compositions; therefore, it is important to understand the effect of these inorganic cations specifically Rb+ on the properties of perovskite struc ...

WILEY-V C H VERLAG GMBH2018

Origin of unusual bandgap shift and dual emission in organic-inorganic lead halide perovskites

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ursula Röthlisberger, Mohammad Ibrahim Dar, Gwénolé Jean Jacopin, Neha Arora, Simone Meloni, Ariadni Boziki

Emission characteristics of metal halide perovskites play a key role in the current widespread investigations into their potential uses in optoelectronics and photonics. However, a fundamental understanding of the molecular origin of the unusual blueshift ...

2016

Impact of alloy disorder on Auger recombination in single InGaN/GaN core-shell microrods

Benoît Marie Joseph Deveaud, Gwénolé Jean Jacopin, Georg Rossbach, Wei Liu

We study the influence of local inhomogeneities on carrier recombination dynamics in single InGaN/GaN core-shell microrods (MRs) by means of time-resolved microphotoluminescence (TRPL) at 10 K. At low carrier density (similar to 10(11) cm(-2)), the carrier ...

2019

Molecular Origin of the Asymmetric Photoluminescence Spectra of CsPbBr3 at Low Temperature

Michael Graetzel, Ursula Röthlisberger, Mohammad Ibrahim Dar, Gwénolé Jean Jacopin, Ariadni Boziki

CsPbBr3 has received wide attention due to its superior emission yield and better thermal stability compared to other organic-inorganic lead halide perovskites. In this study, through an interplay of theory and experiments, we investigate the molecular ori ...

2021

Exciton Drift in Semiconductors under Uniform Strain Gradients: Application to Bent ZnO Microwires

Benoît Marie Joseph Deveaud, Jean-Daniel Ganière, Gwénolé Jean Jacopin, Mehran Shahmohammadi

Optimizing the electronic structures and carrier dynamics in semiconductors at atomic scale is an essential issue for innovative device applications. Besides the traditional chemical doping and the use of homo/heterostructures, elastic strain has been prop ...

American Chemical Society2014

Exciton hopping probed by picosecond time-resolved cathodoluminescence

Benoît Marie Joseph Deveaud, Jean-Daniel Ganière, Gwénolé Jean Jacopin, Mehran Shahmohammadi

The exciton transport is studied in high quality ZnO microwires using time resolved cathodoluminescence. Owing to the available picosecond temporal and nanometer spatial resolution, a direct estimation of the exciton average speed has been measured. When r ...

American Institute of Physics2015

Temperature Dependent Exciton Funnel Dynamics in Uniform Strain Gradient Field Observed by Time-Resolved Photoluminescence

Benoît Marie Joseph Deveaud, Jean-Daniel Ganière, Gwénolé Jean Jacopin, Mehran Shahmohammadi

Elastic strain engineering is an important way to reversibly tune the properties of micro/nanoscale semiconductors for promising applications in the emerging advanced nanotechnologies, such as the strain enhanced high-mobility transistors, nanogenerators, ...

WILEY-V C H VERLAG GMBH2021

Intrinsic and Extrinsic Stability of Formamidinium Lead Bromide Perovskite Solar Cells Yielding High Photovoltage

Shaik Mohammed Zakeeruddin, Mohammad Ibrahim Dar, Gwénolé Jean Jacopin, Fabrizio Giordano, Neha Arora, Norman Pellet, Mojtaba Abdi Jalebi

We report on both the intrinsic and the extrinsic stability of a formamidinium lead bromide [CH(NH2)(2)PbBr3 = FAPbBr(3)] perovskite solar cell that yields a high photovoltage. The fabrication of FAPbBr(3) devices, displaying an outstanding photo voltage o ...

American Chemical Society2016

Core-shell InGaN/GaN nanowire light emitting diodes analyzed by electron beam induced current microscopy and cathodoluminescence mapping

Gwénolé Jean Jacopin, Hua Zhang

We report on the electron beam induced current (EBIC) microscopy and cathodoluminescence (CL) characterization correlated with compositional analysis of light emitting diodes based on core/shell InGaN/GaN nanowire arrays. The EBIC mapping of cleaved fully ...

Royal Soc Chemistry2015

Function Follows Form: Correlation between the Growth and Local Emission of Perovskite Structures and the Performance of Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Mohammad Ibrahim Dar, Gwénolé Jean Jacopin, Neha Arora

Understanding the relationship between the growth and local emission of hybrid perovskite structures and the performance of the devices based on them demands attention. This study investigates the local structural and emission features of CH3NH3PbI3, CH3NH ...

Wiley-Blackwell2017

Photovoltaic and Amplified Spontaneous Emission Studies of High-Quality Formamidinium Lead Bromide Perovskite Films

Mohammad Khaja Nazeeruddin, Benoît Marie Joseph Deveaud, Peng Gao, Wolfgang Richard Tress, Mohammad Ibrahim Dar, Thomas Moehl, Gwénolé Jean Jacopin, Neha Arora, Mahmoud Saeed Qaid Mohammad Hezam

This study demonstrates the formation of extremely smooth and uniform formamidinium lead bromide (CH(NH2)(2)PbBr3 = FAPbBr(3)) films using an optimum mixture of dimethyl sulfoxide and N,N-dimethylformamide solvents. Surface morphology and phase purity of t ...

Wiley-Blackwell2016

Impact of defects on Auger recombination in c-plane InGaN/GaN single quantum well in the efficiency droop regime

Matthieu Jean-Marie Louis Aucouturier, Nicolas Grandjean, Jean-François Carlin, Raphaël Butté, Yixing Chen, Gwénolé Jean Jacopin, Camille Haller, Wei Liu, Thomas Fjord Kjaersgaard Weatherley

We study the impact of non-radiative defects on Auger recombination in c-plane InGaN/GaN single quantum wells (SQWs) in the efficiency droop regime using high injection time-resolved photoluminescence. The defect density in the SQW is controlled by tuning ...

AMER INST PHYSICS2020

Interplay of the photovoltaic and photoconductive operation modes in visible-blind photodetectors based on axial p-i-n junction GaN nanowires

Gwénolé Jean Jacopin

We report on the mixed photovoltaic/photoconductive operation mode of a visible blind photodetector based on GaN nanowires containing a p-i-n junction. The photodetector operates as a photovoltaic device close to zero bias and exhibits a photoconductive ga ...

Amer Inst Physics2014

Electroluminescence of Single InGaN/GaN Micropyramids

Hua Zhang, Gwénolé Jean Jacopin

The results of the fabrication of technological regimes of formation and the study of the optical properties of light emitting diodes (LED) micropyramids based on InGaN/GaN are presented. The structures were formed by the method of Metalorganic vapour-phas ...

PLEIADES PUBLISHING INC2019

Carrier-density-dependent recombination dynamics of excitons and electron-hole plasma in m-plane InGaN/GaN quantum wells

Nicolas Grandjean, Benoît Marie Joseph Deveaud, Raphaël Butté, Gwénolé Jean Jacopin, Wei Liu

We study the carrier-density-dependent recombination dynamics in m-plane InGaN/GaN multiple quantum wells in the presence of n-type background doping by time-resolved photoluminescence. Based on Fermi's golden rule and Saha's equation, we decompose the rad ...

Amer Physical Soc2016

High Open-Circuit Voltage: Fabrication of Formamidinium Lead Bromide Perovskite Solar Cells Using Fluorene-Dithiophene Derivatives as Hole-Transporting Materials

Michael Graetzel, Mohammad Khaja Nazeeruddin, Mohammad Ibrahim Dar, Gwénolé Jean Jacopin, Neha Arora, Paul Gratia, Sadig Aghazada

Four different fluorene dithiophene derivative-based hole-transporting materials (HTMs) (SO7-10) have been synthesized via a facile route and were successfully used in the fabrication of formamidinium lead bromide perovskite solar cells. Detailed character ...

Amer Chemical Soc2016

GaN surface as the source of non-radiative defects in InGaN/GaN quantum wells

Nicolas Grandjean, Jean-François Carlin, Raphaël Butté, Denis Martin, Wei Liu, Gwénolé Jean Jacopin, Camille Haller

Blue light-emitting diodes based on III-nitride semiconductors are nowadays widely used for solid-state lighting. They exhibit impressive figures of merit like an internal quantum efficiency close to 100%. This value is intriguing when considering the high ...

2018

Excitonic Diffusion in InGaN/GaN Core–Shell Nanowires

Jean-Daniel Ganière, Gwénolé Jean Jacopin, Hua Zhang, Mehran Shahmohammadi

We report on the direct observation of the diffusion of carriers in graded InGaN/GaN quantum wells in a nanowire. By probing the local dynamics at the nanoscale, along the wire for different temperatures between 4 and 250 K, we conclude that this diffusion ...

American Chemical Society (ACS)2016

Hopping process of bound excitons under an energy gradient

Benoît Marie Joseph Deveaud, Jean-Daniel Ganière, Gwénolé Jean Jacopin, Mehran Shahmohammadi

We report on the mechanism of hopping for bound excitons under an energy gradient. By means of a Monte-Carlo simulation, we show that this mechanism explains the movement of bound excitons observed experimentally. We show that the speed of the excitons dec ...

American Institute of Physics2014