Publications

2022

Tuning the Charge Transfer in lambda 5 -Phosphinines with Amino-substituents
- Ledos Nicolas
- Sangchai Thitiporn
- Knysh Iryna
- Bousquet Manon
- Manzhi Payal
- Cordier Marie
- Tondelier Denis
- Geffroy Bernard
- Jacquemin Denis
- Bouit Pierre-Antoine
- Hissler Muriel
Organic Letters, American Chemical Society, 2022, 24 (37), pp.6869–6873. We report the substitution of lambda 5-phosphinines (2,6-dicarbonitrile diphenyl-1-λ 5-phosphinine) with amino-group. The impact of these modifications on both the optical and redox properties is investigated using a joint experimental/theoretical approach. In particular, we show that the choice of the donor diphenyl-amino group dramatically impacts the nature of the charge transfer. The use of di(methoxyphenyl)amine redshifts the optical properties and allows thermally activated delayed fluorescent in the solid-state. Finally, we demonstrated that lambda 5-phosphinines with amino-group can be used as active emitter in an electroluminescent device. (10.1021/acs.orglett.2c02846)
DOI : 10.1021/acs.orglett.2c02846
Mirau-based line-field confocal optical coherence tomography for three-dimensional high-resolution skin imaging
- Xue Weikai
- Ogien Jonas
- Bulkin Pavel
- Coutrot Anne-Lise
- Dubois Arnaud
Journal of Biomedical Optics, Society of Photo-optical Instrumentation Engineers, 2022. Significance: Line-field confocal optical coherence tomography (LC-OCT) is a recently introduced high-resolution imaging modality based on a combination of low-coherence optical interferometry and reflectance confocal optical microscopy with line illumination and line detection. Capable of producing three-dimensional (3D) images of the skin with cellular resolution, in vivo, LC-OCT has been mainly applied in dermatology and dermo-cosmetology. The LC-OCT devices capable of acquiring 3D images reported so far are based on a Linnik interferometer using two identical microscope objectives. In this configuration, LC-OCT cannot be designed to be a very compact and light device, and the image acquisition speed is limited. Aim: The objective of this work was to develop a more compact and lighter LC-OCT device that is capable of acquiring images faster without significant degradation of the resolution and with optimized detection sensitivity. Approach: We developed an LC-OCT device based on a Mirau interferometer using a single objective. Dynamic adjustment of the camera frequency during the depth scan is implemented, using a faster camera and a more powerful light source. The reflectivity of the beam-splitter in the Mirau interferometer was optimized to maximize the detection sensitivity. A galvanometer scanner was incorporated into the device for scanning the illumination line laterally. A stack of adjacent B-scans, constituting a 3D image, can thus be acquired. Results: The device is able to acquire and display B-scans at 17 fps. 3D images with a quasiisotropic resolution of ∼1.5 μm (1.3, 1.9, and 1.1 μm in the x; y, and z directions, respectively) over a field of 940 μm × 600 μm × 350 μm (x × y × z) can be obtained. 3D imaging of human skin at cellular resolution, in vivo, is reported. Conclusions: The acquisition rate of the B-scans, at 17 fps, is unprecedented in LC-OCT. Compared with the conventional LC-OCT devices based on a Linnik interferometer, the reported Mirau-based LC-OCT device can acquire B-scans ∼2 times faster. With potential advantages in terms of compactness and weight, a Mirau-based device could easily be integrated into a smaller and lighter handheld probe for use by dermatologists in their daily medical practice. (10.1117/1.JBO.27.8.086002])
DOI : 10.1117/1.JBO.27.8.086002]
Synthesis, crystal structure, tropicity and charge transport properties of diindenothienothiophene derivatives
- Jousselin-Oba Tanguy
- Mamada Masashi
- Wright Karen
- Marrot Jérôme
- Adachi Chihaya
- Yassar Abderrahim
- Frigoli Michel
Journal of Materials Chemistry C, Royal Society of Chemistry, 2022. A set of π-conjugated diindenothienothiophene derivatives (DITTs) which formally possess an extended as-indacene core with 16 π-electrons has been synthesised and their closed-shell configuration has been confirmed by X-ray structure analysis. Bond lengths analysis provides insight into the peculiar bond lengths observed for diindenoacene diradicaloids. The annellation mode at the outer rings has a great impact on the tropicity, optoelectrochemical properties and molecular packing. The featured molecules exhibit low energy band gap with values up to 1.30 eV and have high electron affinities with LUMO energies up to 3.86 eV. Their optical properties are similar to those of benzo-fused indeno[2,1-c]fluorene (BIFs) counterparts possessing formally the as-indacene core. Analysis of the molecule tropicity using NICS and ACID plot shows that the central rings of DITTs are weakly antiaromatic and should be regarded as quinoidal molecules bridged by two sulphur atoms. Three out of four molecules show ambipolar behavior in OFETs with moderate mobilities (10.1039/D2TC01324J)
DOI : 10.1039/D2TC01324J
Influence of the Electron Beam and the Choice of Heating Membrane on the Evolution of Si Nanowires’ Morphology in In Situ TEM
- Shen Ya
- Zhao Xuechun
- Gong Ruiling
- Ngo Eric
- Maurice Jean-Luc
- Roca I Cabarrocas Pere
- Chen Wanghua
Materials, MDPI, 2022, 15 (15), pp.5244. We used in situ transmission electron microscopy (TEM) to observe the dynamic changes of Si nanowires under electron beam irradiation. We found evidence of structural evolutions under TEM observation due to a combination of electron beam and thermal effects. Two types of heating holders were used: a carbon membrane, and a silicon nitride membrane. Different evolution of Si nanowires on these membranes was observed. Regarding the heating of Si nanowires on a C membrane at 800 °C and above, a serious degradation dependent on the diameter of the Si nanowire was observed under the electron beam, with the formation of Si carbide. When the membrane was changed to Si nitride, a reversible sectioning and welding of the Si nanowire was observed. (10.3390/ma15155244)
DOI : 10.3390/ma15155244
Digital histology of tissue with Mueller microscopy and FastDBSCAN
- Lee Hee Ryung
- Lotz Christian
- Kai Groeber Becker Florian
- Dembski Sofia
- Novikova Tatiana
Applied optics, Optical Society of America, 2022, 61 (32), pp.9616. We present the results of the automated post-processing of Mueller microscopy images of skin tissue models with a new fast version of the algorithm of density-based spatial clustering of applications with noise (FastDBSCAN) and discuss the advantages of its implementation for digital histology of tissue. We demonstrate that using the FastDBSCAN algorithm, one can produce the diagnostic segmentation of high resolution images of tissue by several orders of magnitude faster and with high accuracy ( > 97 % ) compared to the original version of the algorithm. (10.1364/AO.473095)
DOI : 10.1364/AO.473095
Circularly polarized light emission by incandescent metasurfaces
- Nguyen Anne
- Hugonin Jean-Paul
- Garcia-Caurel Enrique
- Coutrot Anne-Lise
- Vest Benjamin
- Greffet Jean-Jacques
, 2022, PC12197, pp.PC121970I. (10.1117/12.2632983)
DOI : 10.1117/12.2632983
Optical diagnosis of gastric tissue biopsies with Mueller microscopy and statistical analysis
- Kim Myeongseop
- Lee Hee Ryung
- Ossikovski Razvigor
- Malfait-Jobart Aude
- Lamarque Dominique
- Novikova Tatiana
Journal of the European Optical Society : Rapid publications, European Optical Society, 2022, 18 (2), pp.10. We investigate a possibility of producing the quantitative optical metrics to characterize the evolution of gastric tissue from healthy conditions via inflammation to cancer by using Mueller microscopy of gastric biopsies, regression model and statistical analysis of the predicted images. For this purpose the unstained sections of human gastric tissue biopsies at different pathological conditions were measured with the custom-built Mueller microscope. Polynomial regression model was built using the maps of transmitted intensity, retardance, dichroism and depolarization to generate the predicted images. The statistical analysis of predicted images of gastric tissue sections with multi-curve fit suggests that Mueller microscopy combined with data regression and statistical analysis is an effective approach for quantitative assessment of the degree of inflammation in gastric tissue biopsies with a high potential in clinical applications. (10.1051/jeos/2022011)
DOI : 10.1051/jeos/2022011
Optical diagnosis of gastric tissue biopsies with Mueller microscopy and statistical analysis
- Kim Myeongseop
- Lee Hee Ryung
- Ossikovski Razvigor
- Malfait-Jobart Aude
- Lamarque Dominique
- Novikova Tatiana
Journal of the European Optical Society : Rapid publications, European Optical Society, 2022, 18 (2), pp.10. We investigate a possibility of producing the quantitative optical metrics to characterize the evolution of gastric tissue from healthy conditions via inflammation to cancer by using Mueller microscopy of gastric biopsies, regression model and statistical analysis of the predicted images. For this purpose the unstained sections of human gastric tissue biopsies at different pathological conditions were measured with the custom-built Mueller microscope. Polynomial regression model was built using the maps of transmitted intensity, retardance, dichroism and depolarization to generate the predicted images. The statistical analysis of predicted images of gastric tissue sections with multi-curve fit suggests that Mueller microscopy combined with data regression and statistical analysis is an effective approach for quantitative assessment of the degree of inflammation in gastric tissue biopsies with a high potential in clinical applications. (10.1051/jeos/2022011)
DOI : 10.1051/jeos/2022011
Wafer-scale pulsed laser deposition of ITO for solar cells: reduced damage vs. interfacial resistance
- Smirnov Yury
- Repecaud Pierre-Alexis
- Tutsch Leonard
- Florea Ileana
- Zanoni Kassio P.S.
- Paliwal Abhyuday
- Bolink Henk
- I Cabarrocas Pere Roca
- Bivour Martin
- Morales-Masis Monica
Materials Advances, Royal Society of Chemistry, 2022, 3 (8), pp.3469-3478. Halide perovskite and silicon heterojunction solar cells present sensitive contact layers prone to damage during ITO deposition. We study the effect of ITO pulsed laser deposition pressure on damage mitigation and improved solar cell performance. (10.1039/d1ma01225h)
DOI : 10.1039/d1ma01225h
Visualizing the effects of plasma-generated H atoms <i>in situ</i> in a transmission electron microscope
- Maurice Jean-Luc
- Bulkin Pavel
- Ngo Éric
- Wang Weixi
- Foldyna Martin
- Florea Ileana
- Roca I Cabarrocas Pere
- Béjaud Romuald
- Hardouin Duparc Olivier
European Physical Journal: Applied Physics, EDP Sciences, 2022, 97, pp.7. The radicals and atoms generated by a plasma have the effect, among others, of changing the surface energies of materials, which allows one to prepare nano-objects that would not stabilise in other conditions. This is the case of the Sn catalysed silicon nanowires (NWs) we present in this paper: without plasma, the liquid Sn at the top of NWs is unstable (because Sn naturally wets the Si) so that no growth is allowed, while in presence of the H atoms generated by the plasma, the balance of surface energies is drastically changed; the Sn droplet stabilises and can be used efficiently by the vapour-liquid-solid (VLS) mechanism of growth. Thus, if one wants to study the growth mechanisms of such NWs in situ in the transmission electron microscope (TEM), one has to adapt a plasma system on the TEM. This is precisely what was done at École polytechnique on the NanoMAX environmental TEM. The paper reports on the plasma effects, on the catalyst and on NW growth, recorded in situ in real time, at atomic resolution. The results are discussed in the light of density functional calculations of bare and hydrogenated Si surface energies. (10.1051/epjap/2022210276)
DOI : 10.1051/epjap/2022210276
Qualification of uniform large area multidipolar ECR hydrogen plasma
- Colina-Delacqua L.
- Redolfi M.
- Ouaras Karim
- Naël-Redolfi J.
- Bonnin X.
- Michau A.
- Hassouni K.
- Lombardi G.
Physics of Plasmas, American Institute of Physics, 2022, 29 (4), pp.043508. The design and characterization of a multi-dipolar microwave electron cyclotron resonance (ECR) hydrogen plasma reactor are presented. In this configuration, 16 ECR sources are disposed uniformly along the azimuthal direction at a constant distance from the center of a cylindrical reactor. Several plasma diagnostics have been used to determine key parameters such as neutral species temperature; electron density and temperature; and H+, H2+, and H3+ ion energy distributions. The experimental characterization is supported by electromagnetic and magnetostatic field simulations as well as Particle In-Cell Monte Carlo Collisions simulations to analyze the observed ion energy distribution functions. Especially, we show that both electron density and temperature are spatially uniform, i.e., 1011 cm−3 and 3 eV, respectively. This plasma enables generating ion flux and energy in the ranges 1019–1022 ions m−2 s−1 and few keVs, respectively. The H2+ ion distribution function shows two populations which were attributed to surface effects. These features make this reactor particularly suitable for studying hydrogen plasma surface interaction under controlled conditions (10.1063/5.0083341)
DOI : 10.1063/5.0083341
Organophosphorus emitters for OLEDs
- Hissler Muriel
- Bouit Pierre-Antoine
- Tondelier Denis
- Geffroy Bernard
EPJ Web of Conferences, EDP Sciences, 2022, 266, pp.06006. In this paper, we present the development of OLEDs using organophosphorus derivatives as emitters. In this study, we were able to show that the structural variations carried out on phospholes, phosphinines and phosphepines (functionalization of the phosphorus atom, nature of the substituents) make it possible to modulate the emission wavelengths and, thus, the emission colour of the diodes. Using this concept, we were able to develop TADF and chiral organophosphorus emitters and hybrids emitting at different wavelengths which can be used for the development of OLEDs. The diode structures used are simple and provide high external quantum yields. (10.1051/epjconf/202226606006)
DOI : 10.1051/epjconf/202226606006
Highly emissive layers based on organic/inorganic nanohybrids using Aggregation Induced Emission effect
- Phelipot Jonathan
- Ledos Nicolas
- Dombray Thomas
- Duffy Matthew P
- Denis Mathieu
- Wang Ting
- Didane Yahia
- Gaceur Meriem
- Bao Qinye
- Liu Xianjie
- Fahlman Mats
- Delugas Pietro
- Mattoni Alessandro
- Tondelier Denis
- Geffroy Bernard
- Bouit Pierre-Antoine
- Margeat Olivier
- Ackermann Jörg
- Hissler Muriel
Advanced Materials Technologies, Wiley, 2022, 7 (1), pp.2100876. Fluorescent nanohybrids, based on p-extended hydroxyoxophosphole ligands grafted onto ZnO nanoparticles, were designed and studied. The restriction of the intramolecular motions of the organic fluorophore, through either aggregates' formation in solution or processing into thin films, forms highly emissive materials due to a strong Aggregation Induced Emission effect. Theoretical calculations and XPS analyses were performed to analyze the interactions between the organic and inorganic counterparts. Preliminary results on the use of these nanohybrids as solution-processed emissive layers in Organic Light Emitting Diodes (OLEDs) illustrate their potential for lighting applications. (10.1002/admt.202100876)
DOI : 10.1002/admt.202100876
Depolarization imaging for fast and non-invasive monitoring of cervical microstructure remodeling in vivo during pregnancy
- Rehbinder Jean
- Vizet Jérémy
- Park Junha
- Ossikovski Razvigor
- Vanel Jean-Charles
- Nazac André
- Pierangelo Angelo
Scientific Reports, Nature Publishing Group, 2022, 12 (12321). The cervix plays a crucial role in conception, maintenance of pregnancy, and childbirth. The mechanical properties of a pregnant woman's cervix change dramatically during gestation due to a remodeling of its microstructure, necessary for delivery. However, external factors can accelerate this process and lead to prematurity, the primary cause of perinatal mortality worldwide, due to the inefficiency of existing diagnostic methods. This study shows that polarized light is a powerful tool to probe the cervical microstructure during pregnancy. A wide-field multispectral polarimetric imaging system was fabricated to explore in vivo the cervix of full-term pregnant women. The polarimetric properties of the cervix change significantly with pregnancy progression. In particular, a set of several depolarization parameters (intrinsic and extrinsic) showed a strong linear correlation with gestational age in the red part of the visible spectral range. This trend can be attributed, among other things, to a decrease in collagen density and an increase in hydration of cervical connective tissue. Wide field depolarization imaging is a very promising tool for rapid and non-invasive analysis of cervical tissue in vivo to monitor the steady progression of pregnancy, providing the practitioner with useful information to improve the detection of preterm birth. (10.1038/s41598-022-15852-w)
DOI : 10.1038/s41598-022-15852-w
Si-containing Polycyclic Aromatic Hydrocarbons: Synthesis and Opto-electronic Properties
- Delouche Thomas
- Taifour Ghizlene
- Cordier Marie
- Roisnel Thierry
- Tondelier Denis
- Manzhi Payal
- Geffroy Bernard
- Le Guennic Boris
- Jacquemin Denis
- Hissler Muriel
- Bouit Pierre-Antoine
Chemical Communications, Royal Society of Chemistry, 2022, 58 (1), pp.88-91. We report a straightforward synthesis of Si-containing Polycyclic Aromatic Hydrocarbons (PAHs). The impact of π-extension and exocyclic modifications on both the optical and redox properties is investigated using a joint experimental/theoretical approach. By taking advantage of the solid-state luminescence of these derivatives, electroluminescent devices are prepared. Such preliminary opto-electronic results highlight that these heteroatom-containing PAHs are promising building blocks for organic electronics. (10.1039/D1CC06309J)
DOI : 10.1039/D1CC06309J
Electrical and Electrochemical Sensors Based on Carbon Nanotubes for the Monitoring of Chemicals in Water—A Review
- Cho Gookbin
- Azzouzi Sawsen
- Zucchi Gaël
- Lebental Bérengère
Sensors, MDPI, 2022, 22 (1), pp.218. Carbon nanotubes (CNTs) combine high electrical conductivity with high surface area and chemical stability, which makes them very promising for chemical sensing. While water quality monitoring has particularly strong societal and environmental impacts, a lot of critical sensing needs remain unmet by commercial technologies. In the present review, we show across 20 water monitoring analytes and 90 references that carbon nanotube-based electrochemical sensors, chemistors and field-effect transistors (chemFET) can meet these needs. A set of 126 additional references provide context and supporting information. After introducing water quality monitoring challenges, the general operation and fabrication principles of CNT water quality sensors are summarized. They are sorted by target analytes (pH, micronutrients and metal ions, nitrogen, hardness, dissolved oxygen, disinfectants, sulfur and miscellaneous) and compared in terms of performances (limit of detection, sensitivity and detection range) and functionalization strategies. For each analyte, the references with best performances are discussed. Overall, the most frequently investigated analytes are H+ (pH) and lead (with 18% of references each), then cadmium (14%) and nitrite (11%). Micronutrients and toxic metals cover 40% of all references. Electrochemical sensors (73%) have been more investigated than chemistors (14%) or FETs (12%). Limits of detection in the ppt range have been reached, for instance Cu(II) detection with a liquid-gated chemFET using SWCNT functionalized with peptide-enhanced polyaniline or Pb(II) detection with stripping voltammetry using MWCNT functionalized with ionic liquid-dithizone based bucky-gel. The large majority of reports address functionalized CNTs (82%) instead of pristine or carboxyl-functionalized CNTs. For analytes where comparison is possible, FET-based and electrochemical transduction yield better performances than chemistors (Cu(II), Hg(II), Ca(II), H2O2); non-functionalized CNTs may yield better performances than functionalized ones (Zn(II), pH and chlorine). (10.3390/s22010218)
DOI : 10.3390/s22010218
Grid batch-dependent tuning of glow discharge parameters
- Kazan Ramy
- Bourgeois Gabrielle
- Carisetti Dominique
- Florea Ileana
- Larquet Eric
- Maurice Jean-Luc
- Mechulam Yves
- Ozanam François
- Schmitt Emmanuelle
- Coureux Pierre-Damien
Frontiers in Molecular Biosciences, Frontiers Media, 2022, 9, pp.910218. Sample preparation on cryo-EM grids can give various results, from very thin ice and homogeneous particle distribution (ideal case) to unwanted behavior such as particles around the "holes" or complexes that do not entirely correspond to the one in solution (real life). We recently run into such a case and finally found out that variations in the 3D reconstructions were systematically correlated with the grid batches that were used. We report the use of several techniques to investigate the grids' characteristics, namely TEM, SEM, Auger spectroscopy and Infrared Interferometry. This allowed us to diagnose the origin of grid preparation problems and to adjust glow discharge parameters. The methods used for each approach are described and the results obtained on a common specific case are reported. (10.3389/fmolb.2022.910218)
DOI : 10.3389/fmolb.2022.910218

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