A5034497665- Quantum Dots Synthesis And Properties
- Chalcogenide Semiconductor Thin Films
- Perovskite Materials and Applications
- Advanced Semiconductor Detectors and Materials
- 2D Materials and Applications
- Photonic and Optical Devices
- Gold and Silver Nanoparticles Synthesis and Applications
- Plasmonic and Surface Plasmon Research
- Nanocluster Synthesis and Applications
- Nanowire Synthesis and Applications
- Photonic Crystals and Applications
- Metamaterials and Metasurfaces Applications
- Semiconductor materials and devices
- Supramolecular Self-Assembly in Materials
- Advanced Photocatalysis Techniques
- Copper-based nanomaterials and applications
- Dendrimers and Hyperbranched Polymers
- Thermal Radiation and Cooling Technologies
- Nanomaterials for catalytic reactions
- Semiconductor Quantum Structures and Devices
- Gas Sensing Nanomaterials and Sensors
- ZnO doping and properties
- Visual Attention and Saliency Detection
- Inorganic Chemistry and Materials
- Molecular Communication and Nanonetworks
Nanyang Technological University
2025
Institut des NanoSciences de Paris
2020-2024
Sorbonne Université
2020-2024
Centre National de la Recherche Scientifique
2020-2024
Laboratoire de Physique et d’Étude des Matériaux
2021-2024
Université Paris Sciences et Lettres
2021-2024
ESPCI Paris
2021-2024
Centre de Gestion Scientifique
2023
Université Sorbonne Nouvelle
2023
Université Paris 1 Panthéon-Sorbonne
2022
Semiconductor colloidal nanocrystals are excellent light emitters in terms of efficiency and spectral control. They can be integrated with a metasurface to make ultrathin photoluminescent devices reduced amount active material perform complex functionalities such as beam shaping or polarization To design metasurface, quantitative model the emitted power is needed. Here, we report design, fabrication, characterization ∼300 nm thick light-emitting device combining plasmonic an ensemble...
Transferring nanocrystals (NCs) from the laboratory environment toward practical applications has raised new challenges. HgTe appears as most spectrally tunable infrared colloidal platform. Its low-temperature synthesis reduces growth energy cost yet also favors sintering. Once coupled to a read-out circuit, Joule effect aggregates particles, leading poorly defined optical edge and large dark current. Here, we demonstrate that CdS shells bring expected thermal stability (no redshift upon...
Abstract The limited investigation of the optical properties HgTe nanocrystal (NC) thin films has become a bottleneck for electromagnetic design devices. Using broadband ellipsometry, refractive index ( n ) and extinction coefficient k are determined series NC relevant to infrared sensing applications. Electromagnetic simulations reveal that value can conveniently be approximated by its mean spectral = 2.35 ± 0.15. This complex is then used diode with i) reduced amount Hg containing material...
Two-dimensional II–VI semiconductor nanoplatelets (NPLs) present exceptionally narrow optical features due to their thickness defined at the atomic scale. Because drives band-edge energy, its control is of paramount importance. Here, we demonstrate that native carboxylate ligands can be replaced by halides partially dissolve cadmium chalcogenide NPLs edges. The released monomers then recrystallize on wide top and bottom facets, leading an increase in NPL thickness. This...
Optical microcavities are widely used to confine photons for exciton-polariton formation. However, their compact design often imposes limitations on spatial freedom, particularly in controlling the cavity length with nanometer precision required effective coupling excitons. Existing methods tuning resonances by integrating cavities dynamic structures lack sufficient resolution or a complex operation. Here, we introduce multiresonant microcavity array that provides full spectral selection of...
Mercury telluride (HgTe) nanocrystals are among the most versatile infrared (IR) materials with absorption of lowest energy optical which can be tuned from visible to terahertz range. Therefore, they have been extensively considered as near IR emitters and absorbers for low-cost detectors. However, electroluminescence HgTe remains poorly investigated despite its ability go toward longer wavelengths compared traditional lead sulfide (PbS). Here, we demonstrate a light-emitting diode (LED)...
HgTe colloidal nanocrystals (NCs) have become a promising building block for infrared optoelectronics. Despite their cubic zinc blende lattice, NCs tend to grow in multipodic fashion, leading poor shape and size control. Strategies obtain with well-controlled sizes shapes remain limited sometimes challenging handle, increasing the need new growth process. Here, we explore synthetic route via seeded growth. In this approach, small seeds are nucleated first step, they show narrow bright...
HgTe nanocrystals (NCs) enable broadly tunable infrared absorption, now commonly used to design light sensors. This material tends grow under multipodic shapes and does not present well-defined size distributions. Such point generates traps reduces the particle packing, leading a reduced mobility. It is thus highly desirable comprehensively explore effect of shape on their performance. Here, we show, using combination electron tomography tight binding simulations, that charge dissociation...
The crystal structure of atomically defined colloidal II-VI semiconductor nanoplatelets (NPLs) induces the self-assembly organic ligands over thousands square nanometers on top and bottom basal planes these anisotropic nanoparticles. NPLs curl into helices under influence surface stress induced by ligands. We demonstrate control radii NPL through described as an anchoring group aliphatic chain a given length. A mechanical model accounting for misfit strain between inorganic core predicts...
Intraband absorption in doped nanocrystals offers an interesting alternative to narrow-band-gap materials explore mid-infrared optoelectronic device designs. However, the performance of such a clearly lags behind ones relying on intrinsic materials. Livache et al. proposed dye-sensitized approach overcome limitations observed from intraband (high dark current, slow response, low activation energy), where absorber is coupled with undoped material, which takes care charge conduction. Here, we...
Abstract HgTe nanocrystals offer a unique spectral tunability with both absorption and emission covering the near mid‐infrared as well THz window. Nevertheless, very limited amount of work is dedicated to electroluminescence from this material. An efficient diode not only requires designing structure that achieves high electrical efficiency (i.e., electron hole injections), but also finding way efficiently extract emitted photons. The shift visible infrared certainly demands revisiting...
Abstract Nanocrystals (NCs) are now established building blocks for optoelectronics and their use as down converters large gamut displays has been first mass market. NC integration relies on a combination of green red NCs into blend, which rises post-growth formulation issues. A careful engineering the may enable dual emissions from single population violates Kasha’s rule, stipulates that emission should occur at band edge. Thus, in addition to an attentive control alignment obtain signals,...
After the use of nanocrystals as light downconverters, infrared sensing appears to be one first market applications where they can used while being both electrically and optically active. Over recent years, tremendous progress has been achieved, leading an apparent rise in technological-readiness level (TRL). So far, efforts have focused on PbS for operation near-infrared. Here, we focus HgTe since its narrower band gap offers more flexibility explore extended short-wave midwave infrared. We...
II–VI two-dimensional (2D) nanoplatelets (NPLs) exhibit the narrowest optical features among nanocrystals (NCs). This property remains true for Hg-based NPLs, despite a cation exchange procedure to obtain them from Cd-based which leads structural defects (poorly defined edges and voids) inducing inhomogeneous broadening. Here, we propose an optimized solvent, surface chemistry, reaction conditions are rationally considered. The is applied growth of alloyed HgSe1–xTex NPLs with various...
Abstract Nanocrystals (NCs) have reached a high level of maturity, enabling their integration into optoelectronic devices. The next challenge is the combination several types devices one complex system to achieve better on‐chip integration. Here, an all‐HgTe‐NC active imaging setup operating in short‐wave infrared (IR) focused on. First, design optimized IR light‐emitting diode (LED) It shown that halide technology processing enables increase electroluminescence signal by factor 3, while...
While the integration of nanocrystals as an active medium for optoelectronic devices progresses, light management strategies are becoming required. Over recent years, several photonic structures (plasmons, cavities, mirrors, etc.) have been coupled to nanocrystal films shape absorption spectrum, tune directionality, and so on. Here, we explore a equivalent acoustic Helmholtz resonator propose design that can easily be fabricated. This geometry combines strong electromagnetic field...
As the field of nanocrystal-based optoelectronics matures, more advanced techniques must be developed in order to reveal electronic structure nanocrystals, particularly with device-relevant conditions. So far, most efforts have been focused on optical spectroscopy, and electrochemistry where an absolute energy reference is required. Device optimization requires probing not only pristine material but also its actual environment (i.e., surrounded by a transport layer electrode, presence...
Optoelectronic devices rely on conductive layers as electrodes, but they usually introduce optical losses that are detrimental to the device performances. While use of transparent oxides is established in visible region, these materials show high at longer wavelengths. Here, we demonstrate a photodiode based metallic grating acting an electrode. The generates multiresonant photonic structure over diode stack and allows strong broadband absorption. obtained achieves highest performances...
Infrared nanocrystals are promising building blocks for the design of low-cost infrared sensors. Vertical geometry diode is, among possible geometries, one that has led to best performance so far. However, this suffers from a lack tunability after its fabrication, slowing down improvements. Here, we demonstrate gate control on vertical in which active layer is made HgTe NCs absorbing extended short-wave (2.5 μm). To reach goal, take advantage electrostatic transparency graphene, combined...
Abstract The design of infrared nanocrystals‐based (NCs) photodiodes faces a major challenge related to the identification barriers with well‐suited band alignment or strategy finely control carrier density. Here, this study explores general complementary approach where density is achieved by coupling an NC layer ferroelectric material. up‐and‐down change in polarization directly impacts electronic structure, resulting formation lateral pn junction. This effect uncovered using nano X‐ray...
In the visible range, 2D nanoplatelets (NPLs) have brought significant benefits compared to their 0D counterpart with an inherently anisotropic emission, a narrower photoluminescence (PL) signal, and new degrees of freedom design heterostructures. Compared properties cadmium chalcogenide NPLs in visible, similar research is still mostly lacking infrared, spite existing synthetic paths obtain narrow band gap semiconductors colloidal form. Here, we focus on HgTe show how PL can be stabilized...
II–VI semiconductor nanoplatelets have emerged as promising candidates for various applications, owing to their tunable optical properties dictated by thickness and compositions. In the realm of infrared technology, mercury chalcogenides stand out particularly materials optoelectronic applications. However, direct synthesis 2D particles in this category remains challenging, thus prompting exploration alternative methods such cation exchange. Here, we demonstrate that exchange process from...