A5080171651- 2D Materials and Applications
- Perovskite Materials and Applications
- Chalcogenide Semiconductor Thin Films
- Semiconductor Quantum Structures and Devices
- Graphene research and applications
- Terahertz technology and applications
- Quantum Dots Synthesis And Properties
- Plasmonic and Surface Plasmon Research
- Semiconductor materials and interfaces
- Molecular Junctions and Nanostructures
- Organic and Molecular Conductors Research
- Quantum and electron transport phenomena
- Photonic and Optical Devices
- Advanced Thermoelectric Materials and Devices
- Quantum Information and Cryptography
- Advanced Semiconductor Detectors and Materials
- Phase-change materials and chalcogenides
- Nanowire Synthesis and Applications
- Solid-state spectroscopy and crystallography
- Topological Materials and Phenomena
- Boron and Carbon Nanomaterials Research
École Normale Supérieure
2025
Sorbonne Université
2022-2024
Centre National de la Recherche Scientifique
2022-2024
École Normale Supérieure - PSL
2022-2024
Sorbonne Paris Cité
2022-2024
Université Paris Cité
2022-2024
Laboratoire de Physique de l'ENS
2024
Université Paris Sciences et Lettres
2022-2024
University of Carthage
2016-2022
École Supérieure des Sciences de l'Ingénierie Commerciale
2020-2021
Van der Waals heterostructures have promised the realisation of artificial materials with multiple physical phenomena such as giant optical nonlinearities, spin-to-charge interconversion in spintronics and topological carrier protection, a single layered device through an infinitely diverse set quantum materials. However, most efforts only focused on exfoliated material that inherently limits both dimensions scalability for applications. Here, we show epitaxial growth large area insulators...
We show that CdSe nanoplatelets are a model system to investigate the tunability of trions and excitons in laterally finite 2D semiconductors.
Abstract Platinum diselenide () is a promising two‐dimensional (2D) material for the terahertz (THz) range as, unlike other transition metal dichalcogenides (TMDs), its bandgap can be uniquely tuned from semiconductor in near‐infrared to semimetal with number of atomic layers. This gives unique THz photonic properties that layer‐engineered. Here, we demonstrate controlled nonlinearity—tuned monolayer bulk —can realized wafer size polycrystalline through generation ultrafast photocurrents and...
PtSe_{2} is a van der Waals material transitioning from an indirect band gap semiconductor to semimetal with increasing thickness. Its absorption threshold has been conjectured originate interband transitions. By quantitative comparison between broadband (0.8-3.0 eV) optical of high-quality exfoliated crystals and DFT ab initio simulations, we prove instead that the arises only direct This understanding allows us shed light on semiconductor-to-semimetal transition in emblematic strongly...
Disorder derived from defects or strain in monolayer TMDs can lead to a dramatic change the physical behavior of interband excitations, producing inhomogeneous spectral broadening and localization; leading radiative lifetime increase. In this study, we have modeled disorder surface sample through randomized potential WSe2. We show that model allows us simulate spectra localized exciton states as well their lifetime. context, give an depth study influence parameters on optical properties...
Abstract Unlike traditional group‐6 transition metal dichalcogenides (TMDs), group‐10 TMDs such as PtSe 2 and PdTe possess highly tuneable indirect bandgaps, transitioning from semiconducting in the near‐infrared to semimetal behavior with a number of monolayers (MLs). This opens up possibility TMD‐based mid‐infrared terahertz optoelectronics. Despite this large potential, optical properties materials have shown an extremely disparity between that predicted measured. For example, simulations...
The ultrathin transition metal dichalcogenides (TMDs) have emerged as promising materials for various applications using two dimensional semiconductors. They attracted increasing attention due to their unique optical properties originate from neutral and charged excitons. In this paper, we study the strong localization of exciton center-of-mass motion within random potential fluctuations caused by monolayer defects. Here, report negatively formation in TMDs, notably tungsten disulfide WS2....
Excitonic effects play an important role on the optoelectronic behavior of atomically thin two-dimensional (2D) crystals WS2 transition metal dichalcogenide. In this paper, neutral and charged exciton behaviors in monolayer are handled within effective-mass approximation for which critical parameters ensured from our ab initio calculations. Firstly, we reveal series with a novel energy dependence orbital angular momentum. Considerable control dielectric environment excitons binding energies...
Photoluminescence spectra show that monolayer transition-metal dichalcogenides (ML-TMDs) possess charged exciton binding energies, conspicuously similar to the energy of optical phonons. This enigmatic coincidence has offered opportunities investigate many-body interactions between trion ${X}_{\ensuremath{-}}$, $X$, and phonon led efficient excitonic anti-Stokes processes with potential for laser refrigeration harvesting. In this study, we in ${\mathrm{WSe}}_{2}$ materials, matches two...
We investigate the lateral size tunability of exciton diffusion coefficient and mobility in colloidal quantum wells by means line width analysis theoretical modeling.
As for many technological applications, excitation transport determines their performance, we investigate the THz conductivity of electrons, holes, excitons, and trions in 2D semiconductor nanoparticles. While non-Drude-like frequency response charge carriers these systems has been established recently, responses excitons remain not fully understood. We show that exciton polarizability is related to intraexcitonic transitions between different states relative motion independent...
Strong polarization-dependent effects on the optical response in low-symmetry orthorhombic crystal structure of GeS and emergence mixed exciton states due to anisotropy-induced symmetry breaking.
The ultrathin transition metal dichalcogenides (TMDs) have emerged as promising materials for various applications using two dimensional (2D) semiconductors. They attracted increasing attention due to their unique optical properties originate from neutral and charged excitons. Here, we report negatively exciton formation in monolayer TMDs, notably tungsten disulfide WS2. Our theory is based on an effective mass model of excitons, parameterized by ab-initio calculations. Taking into the...
$\rm{PtSe_2}$ is a van der Waals material transiting from an indirect semiconductor to semimetal with increasing thickness. Its absorption threshold has been conjectured originate interband transitions. By quantitative comparison between wideband optical ($0.8 - 3.0\,\rm{eV}$) of high-quality exfoliated crystals and ab-initio simulations, we prove instead that the arises only direct This understanding allows us shed new light on transition explore effect stacking excitons absorption.
Exciton kinetics in transition‐metal dichalcogenide materials is highly dependent to the experimental conditions and quality of sample. This study presents a comprehensive model comprising complete set rate equations, which account for charge transfer among multiexcitonic channels including bright dark excitons, trions, localized investigate dynamics excitons monolayer WSe 2 . The exciton involving both intra‐ intervalley scattering discussed. In this respect, high samples, it proved that...
We introduce a response theory based transformation for excitonic polarizability into mobility, which allows an in-depth analysis of optical pump-THz probe conductivity experiments, and compare the results with those conventional oscillator model. THz spectroscopy is high interest e.g. investigations in bandwidth low noise nanoelectronics or solar energy harvesting nanomaterials. In contrast to simple ω scaling estimated static polarizability, suggested literature, appropriate spectral...
Our results predict strongly field-dependent nonlinear charge carrier mobility and intra-pulse gain in semiconductor nanostructures using master equations. The size temperature dependence is analyzed.
Platinum diselenide (PtSe2) is a promising two-dimensional (2D) material for the terahertz (THz) range as, unlike other transition metal dichalcogenides (TMDs), its bandgap can be uniquely tuned from semiconductor in near-infrared to semimetal with number of atomic layers. This gives unique THz photonic properties that layer-engineered. Here, we demonstrate controlled nonlinearity - monolayer bulk PtSe2 realised wafer size polycrystalline through generation ultrafast photocurrents and...
Two-dimensional (2D) layered transition metal dichalcogenides (TMDs) semiconductors such as MoS2, MoSe2, WS2,WSe2 have established themselves strong contenders for next-generation electronics and optoelectronics they aroused great attention due to their peculiar physical properties, in particular the electron-hole interaction.We present a theoretical model based on non-local dielectric screening potential show impact of length reduced mass exciton binding energy.We will also determine...
Structural defects can crucially impact the optical response of monolayer (ML) thick materials as they enable trapping sites for excitons. These trapped excitons appear in photoluminescence spectra new emissions below free bright exciton and it be exploited single photon (SPE). In this work we outline criteria, within our frame work, by which emission detected two dimensional explore how these criteria fulfilled atomically thin transition metal dichalcogenides (TMD). particular, model effect...
The investigation of the fluctuations and their influence on exciton in perovskite structure is topical. These can be due to prolongation annealing or increasing temperature monolayers. This fact generates structural imperfections, which may arise from vacancies lattice defects. In this work, we propose a theoretical approach order study optical properties characterized by excitons (RNH3)2(CH3NH3)p−1PbpI3p+1 structures. For high quality samples, investigate free taking into account quantum...
To fully explore exciton-based applications and improve their performance, it is essential to understand the exciton behavior in anisotropic materials. Here, we investigate optical properties of excitons GeS encapsulated by h-BN, using different approaches that combine polarization- temperature-dependent photoluminescence (PL) measurements, \textit{ab initio} calculations, effective mass approximation (EMA). Using Bethe-Salpeter Equation (BSE) method, found absorption spectra are...
As a two-dimensional (2D) material for terahertz (THz) applications, platinum diselenide (PtSe <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> ) can be uniquely tuned from semiconductor in the near infrared to semimetal with number of atomic layers, contrast other transition metal dichalcogenides (TMDs). Consequently, has unique photonic properties at THz frequencies that enhanced by layer engineering. Here, we demonstrate controlled...