Publications by Gwénolé Jean Jacopin

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

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

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

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

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

Cyclopentadithiophene-Based Hole-Transporting Material for Highly Stable Perovskite Solar Cells with Stabilized Efficiencies Approaching 21%

Michael Graetzel, Shaik Mohammed Zakeeruddin, Gwénolé Jean Jacopin, Mohammad Ibrahim Dar, Michael Bauer, Neha Arora, Ryusuke Uchida, Yuhang Liu, Seckin Akin

There is an urge to develop new hole-transporting materials (HTMs) for perovskite solar cells (PSCs), which can yield comparable power conversion efficiencies (PCEs) yet mitigate the issue of stability associated with the state-of-the-art HTM Spiro-MeOTAD. ...

AMER CHEMICAL SOC2020

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

Jean-François Carlin, Nicolas Grandjean, Raphaël Butté, Camille Haller, Yixing Chen, Gwénolé Jean Jacopin, 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

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

Benoît Marie Joseph Deveaud, Christian Mounir, Georg Rossbach, Gwénolé Jean Jacopin, 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

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

Optical absorption and oxygen passivation of surface states in III-nitride photonic devices

Jean-François Carlin, Nicolas Grandjean, Raphaël Butté, Gwénolé Jean Jacopin, Ian Michael Rousseau, Gordon Jens Callsen

2018

Spatially dependent carrier dynamics in single InGaN/GaN core-shell microrod by time-resolved cathodoluminescence

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

AIP American Institute of Physics2018

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

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

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

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

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

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

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

Enhancement of Auger recombination induced by carrier localization in InGaN/GaN quantum wells

Benoît Marie Joseph Deveaud, Nicolas Grandjean, Raphaël Butté, Mehran Shahmohammadi, Georg Rossbach, Lise Lahourcade, Gwénolé Jean Jacopin, Wei Liu

The origin of efficiency droop in state-of-the-art quality In GaN/GaN and GaN/AlGaN quantum wells (QWs) grown on various crystal planes is studied by means of time-resolved photoluminescence spectroscopy associated with a precise determination of the QW ca ...

Amer Physical Soc2017

Burying non-radiative defects in InGaN underlayer to increase InGaN/GaN quantum well efficiency

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

The insertion of an InGaN underlayer (UL) is known to strongly improve the performance of InGaN/GaN quantum well (QW) based blue light emitting diodes (LEDs). However, the actual physical mechanism responsible for it is still unclear. We thus conduct a sys ...

American Institute of Physics2017

Propagating Polaritons in III-Nitride Slab Waveguides

Jean-François Carlin, Nicolas Grandjean, Raphaël Butté, Gwénolé Jean Jacopin, Joachim Armand Simonne Ciers

We report on III-nitride waveguides with c-plane GaN/(Al,Ga)N quantum wells in the strong light-matter coupling regime supporting propagating polaritons. They feature a normal-mode splitting as large as 60 meV at low temperatures thanks to the large overla ...

American Physical Society (APS)2017

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

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

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

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

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

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

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

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

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, Paul Gratia, Gwénolé Jean Jacopin, Mohammad Ibrahim Dar, Sadig Aghazada, Neha Arora, Filippo de Angelis

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

Optical properties of nearly lattice-matched GaN/(Al,In)N quantum wells

Jean-François Carlin, Nicolas Grandjean, Raphaël Butté, Gwénolé Jean Jacopin, Gediminas Liaugaudas

We report a systematic study of the photoluminescence (PL) properties of a series of nearly lattice-matched (LM) GaN/(Al,In)N single quantum well (SQW) samples, with well thickness ranging from 1.5 to 5 nm, grown by metalorganic vapor phase epitaxy. Temper ...

Amer Inst Physics2016

Excitonic Diffusion in InGaN/GaN Core–Shell Nanowires

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

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