Publications

2026

• Material and Circuit Routes to Muller C-Elements in Organic Mixed Ionic-Electronic Conductors
  
  • Yoon Yeohoon
  • Li Zonglong
  • Messer Tobias
  • Prudnikov Nikita
  • Meier Tommy
  • Ditzer Oliver
  • Li Peiyun
  • Solgi Ali
  • Teuerle Laura
  • Lissel Franziska
  • Sun Ningwei
  • Leo Karl
  • Calvet Laurie E
  • Kleemann Hans
  , 2026.
• Interfacial Conditioning for High-Brightness 28 mm2 Active-Area Phenylpropylamine-Capped CsPbBr3 Perovskite Nanocrystal Light-Emitting Diodes Synthesized by a Modified Ligand-Assisted Reprecipitation Method
  
  • Ruby Ernest
  • Alamri Rafa
  • Alaneazi Rakan
  • Trippé-Allard Gaëlle
  • Guiblin Nicolas
  • Tran Jacqueline
  • Vallet Maxime
  • Dembélé Kassiogé
  • Foldyna Martin
  • Deleporte Emmanuelle
  • Bonnassieux Yvan
  • Tondelier Denis
  • Mayer Cédric
  ACS Applied Materials & Interfaces, Washington, D.C. : American Chemical Society, 2026, 18 (38), pp.52932-52950. Abstract Processing-induced interfacial losses limit perovskite nanocrystal light-emitting diodes (PeLEDs) at display-relevant device areas, yet the steps responsible are rarely identified with statistical confidence beyond champion-device reporting. Here, we combine an all-inorganic CsPbBr3 emitter with a replicated factorial study at 28 mm2 active area. Nanocrystals capped with phenylpropylamine (PPA) by a room-temperature modified ligand-assisted reprecipitation (MLARP) route are deposited as two sequential films separated by a ∼2.8 nm polyvinylpyrrolidone (PVP) interlayer, with mild vacuum conditioning before the top layer. Seven of thirteen architectures were replicated over two fabrication sessions, giving 71 functional devices from 84 (84.5% yield). A matched 2 × 2 factorial ANOVA identifies vacuum conditioning as the dominant factor for EQE (partial η2 = 0.90), with a smaller but significant PVP contribution (p = 0.006) and a significant PVP × vacuum interaction for maximum luminance (p < 0.001). The combined route gives a median EQEmax of 12.2% (IQR 0.5%) at 12/12 yield and a champion device with EQEmax = 13.23% at 520 nm, 21,537 cd.m–2, 30.8 lm.W–1 at 100 cd.m–2, 1.7% roll-off at 10 mA.cm–2, and encapsulated τ50 = 3 h at 200 cd.m–2, measured in an integrating sphere. Photoluminescence lifetimes recover from 5.0 to 14.9 ns in the bilayer and the corresponding photoluminescence quantum yield from 8.9% to 28.7%. Across solution, film and both half-device stacks the quantum yield scales linearly with the amplitude-weighted lifetime at a common radiative rate, placing these losses in nonradiative channels and consistent with reduced interfacial quenching. At the same time, transfer-matrix modeling shows outcoupling to be emitter-position dependent (10.4% vs 13.3%), so radiative, transport, and optical contributions remain unseparated. The PVP/vacuum route defines a statistically robust processing window for nanocrystal PeLEDs at a 28 mm2 active area. (10.1021/acsami.6c13884)
  DOI : 10.1021/acsami.6c13884
• Influence of chemical and morphological properties on the mid-infrared refractive indices of Titan aerosol analogs
  
  • Perrin Zoé
  • Drant Thomas
  • Caurel Enrique Garcia
  • Brubach Jean‐blaise
  • Ruscassier Nathalie
  • Gautier Thomas
  • Sciamma-O’brien Ella
  • Vettier Ludovic
  • Chatain Audrey
  • Guaitella Olivier
  • Carrasco Nathalie
  Astronomy & Astrophysics - A&A, EDP Sciences, 2026, 713, pp.A199. The intrinsic properties of aerosols in Titan's atmosphere are one of the main sources of uncertainty when interpreting and understanding observations of its surface and atmosphere. The optical properties of the solid material have been recovered for both of Titan's aerosols using remote-sensing observations and laboratory analogs. Significant differences are observed in the refractive indices reported in the literature. For laboratory-generated solid analogs, these discrepancies in the refractive indices can originate from the different experimental factors influencing the morphological and chemical properties of solid samples, for example the energy distribution, gas flow rate, and/or gas temperature. In this study, we report new refractive indices, n and k, in the mid-infrared spectral range (2-20 µm) determined on Titan aerosol analogs with different morphological and chemical properties. We compare in detail the differences in optical properties of thin films, commonly used for refractive index measurements, and compressed pellets of quasispherical powders. Using transmission spectroscopy and reflection Mueller ellipsometry, we find that compressed powders are more absorbent than their film equivalent, with increased signature strengths of (hetero-)aromatic and amine features in agreement with a higher nitrogen-to-carbon ratio compared to the film analogs. Finally, we observe that the reflective power of these pellet analogs is not only affected by the refractive index (n) but also significantly by the inter-grain porosity. (10.1051/0004-6361/202554328)
  DOI : 10.1051/0004-6361/202554328
• Probabilistic Computing with Neuromorphic Elements
  
  • Li Zonglong
  • Calvet Laurie E
  , 2026. This paper presents a compact and low-power approach to probabilistic inference based on time-domain analog computation. The proposed system implements a Bayesian classifier using neuromorphic circuit elements simulated in a 130 nm CMOS technology. Probabilities are encoded in the duty cycle of deterministic spiking signals generated by neuron circuits, while likelihood functions are directly embedded in the parameters of synapse-like analog circuits. Posterior probabilities are obtained through temporal interactions between these signals using simple circuit primitives, notably an analog coincidence detection or a Muller C-element. The final decision is determined using a time-to-first-spike encoding scheme. In contrast to prior hardware implementations that rely on stochastic sampling, memory-based representations, or explicit evaluation of probabilistic graphs, the proposed approach performs inference through the continuous-time dynamics of a statically configured analog circuit. This avoids random-number generation for probability-stream generation, explicit memory access and analog-to-digital conversion during inference. The approach is validated through circuit-level simulations on a breast cancer classification task, achieving accuracies of 73–90%, comparable to software implementations, while operating in the μW power range. These results demonstrate a compact and energy-efficient solution for low-dimensional probabilistic inference, particularly suited for near-sensor and edge computing applications.
• Structure of microlayer at water pool boiling for various bubble growth rates
  
  • Le Houedec Corentin
  • Zajec Boštjan
  • Tecchio Cassiano
  • Roca I Cabarrocas Pere
  • Bulkin Pavel
  • Nikolayev Vadim
  Journal of Fluid Mechanics, Cambridge University Press (CUP), 2026, 1035, pp.A39. The growth of a single vapour bubble in a saturated pool of boiling water at atmospheric pressure on a transparent heater is investigated experimentally. The study focuses on a several microns thick liquid layer (called a microlayer) that can form between the heater and the bubble. The microlayer profile, the wall temperature distribution and the overall bubble shape are measured simultaneously and synchronously by white light interferometry, infrared thermography and sidewise shadowgraphy. To study the microlayer dynamics for different bubble growth rates, artificial cavities of different sizes were used. These control the wall superheating required for the bubble nucleation, i.e. the nucleation barrier. Both the bubble growth at its inertial stage and the microlayer parameters are found to be almost independent of the applied heat flux and controlled by the nucleation barrier only. The microlayer thickness and its area increase with the nucleation barrier. A model of microlayer formation based on an analogy with the Landau–Levich film deposition is further developed. By using it, the initial microlayer thickness, the time of microlayer formation at a given distance from the bubble centre and the radius of curvature of the bubble foot edge are recovered from the experimental data. The radius of curvature varies in time like the bubble radius, thus suggesting a self-similar bubble growth at its initial inertial stage. The coherency of the above model with the experimental results shows the model’s validity. (10.1017/jfm.2026.11566)
  DOI : 10.1017/jfm.2026.11566
• Synthesis of cross-linkable polymer-based electron transport layers for perovskite solar cells
  
  • Percey Charline
  • Alayane Fatima
  • Nahdi Hindia
  • Oswald Frédéric
  • Lartigau-Dagron Christine
  • Bousquet Antoine
  , 2026. In recent years, perovskite solar cells have attracted considerable interest due to their high efficiencies (over 27%), lightweight and independence from light quality. However, these cells are sensitive to external conditions such as moisture and oxygen, which limits the deployment of this technology on a larger scale. To prevent this degradation, some research has focused on charge transport layers in order to improve their interface with perovskite and act as a protective layer for the latter, thereby improving its stability. In this context, our project aims to developp cross-linkable polymer-based electron transport layers in order to improve the stability and the lifetime of perovskite solar cells. To do so, we designed different molecules based on an alternation of perylene diimide or naphthalene diimide structures (strong electron acceptor units) with a non-conjugated spacer within the chain backbone, instead of lateral chains, to improve the solubility and limit the visible absorbance of our materials. (10.29363/nanoge.hopv.2026.073)
  DOI : 10.29363/nanoge.hopv.2026.073
• Investigation of Novel Cross-linked Electron Transport Layers for Perovskite Solar Cells
  
  • Alayane Fatima
  • Cherradi Abdelhaq
  • Percey Charline
  • Nahdi Hindia
  • Bonnassieux Yvan
  • Gohier Frederic
  • Bousquet Antoine
  • Lartigau-Dagron Christine
  • Oswald Frederic
  • Blanchard Philippe
  , 2026. At the beginning of the 21 st century, carbon neutral and sustainable energy sources need to be considered instead of exhaustible fossil fuels to meet the growing demand and combat global warming. Within this very challenging race for alternative energy sources, metal halide perovskite solar cells (PSCs) have undergone unprecedented progress with efficiencies reaching now 26.95% and even over 30% in tandem configuration 1 and sparked great excitement in the photovoltaics community due to their flexibility and ability to be synthesized at low cost However, since hybrid halide perovskites have a highly ionic character, they can decompose under external stresses such as moisture, solvents and heating cycles. 2,3,4 Reducing environmental stresses imposed by moisture or oxygen for example, in order to improve the longterm stability of perovskite solar cells, is critical to the deployment of this technology.<p>In this communication, we will discuss the preliminary development of new electron transport layers (ETL) and their use in inverted perovskite solar cells (PSCs). The present study concentrated on two distinct methodologies, utilizing small molecules in one case and polymers in the other. The utilization of these materials has the potential to create a more compact layer, thereby protecting the perovskite layer from oxygen and water. This is a significant challenge in the field of PSCs and requires further study. 5 Crosslinking has been demonstrated to enhance mechanical strength, a critical factor in ensuring durability. Furthermore, cross-linkable ETLs have the potential to act as an insulating layer against harmful environments and for lead sequestration. Moreover, these novel materials were incorporated into devices for the purpose of studying the stability of perovskite solar cells, whilst ensuring the continued efficiency of the devices.</p>
• Tuning the optoelectronic properties of NiOx thin films by atomic layer deposition with a precise incorporation of aluminum atoms
  
  • Coutancier Damien
  • Pinal Yann
  • Priaud Tristan
  • Johnson Erik V
  • Béchu Solène
  • Bouttemy Muriel
  • Schneider Nathanaelle
  Journal of Vacuum Science & Technology A, American Vacuum Society, 2026, 44 (3), pp.032410. Nickel oxide (NiO) is a promising p-type semiconductor widely explored for various applications. A key challenge in producing functional NiOx films—particularly with suitable optoelectronic properties and well-defined valence and conduction band positions—lies in achieving precise control over the material’s substoichiometry. We investigate the processes and outcomes involved in incorporating aluminum (Al) atoms during the fabrication of nickel oxide films by atomic layer deposition when using bis(N,N′-di-t-butylacetamidinato)nickel(II) [Ni(amd)2], trimethyl aluminum, and water as the growth precursors to address this challenge. By using both a supercycle technique and tuning the pulse sequence, very fine control over the incorporation of Al into the matrix is demonstrated. This incorporation impacts the film properties in myriad ways, changing the conductivity by 5 orders of magnitude, while also decreasing its optical transparency and decreasing its crystallinity. Further characterization by quartz-crystal microbalance and x-ray photoelectron spectroscopy (XPS) reveals that choosing the pulse sequence and thereby modifying the reactive film surface observed by the Al and Ni precursors dramatically impact their relative uptake into the film. High-resolution XPS measurements at the surface and within the layers further show the fine structure details of this uptake. The incorporation of Al correlates with the detection of a low energy Ni contribution in the films, whose proportion increases with the Al fraction and C content of the films, this latter presenting a specific C signature. These observations suggest either Ni—O—Al films composed of an intermixed compound of Ni—Al—O—C or NiOx films with small AlOx domains and incorporated nickel carbide. (10.1116/6.0005334)
  DOI : 10.1116/6.0005334
• Operando XPS monitoring of MoS2 nanoflake nucleation on carbon nanotubes via integrated CVD-MBE
  
  • Taoum Haifa
  • Ezzedine Mariam
  • Florea Ileana
  • Cojocaru Costel-Sorin
  npj 2D Materials and Applications, Nature, 2026. Hybrid nanostructured materials have attracted significant attention due to their robust multifunctional properties. Among them, 2D@1D nanostructures are particularly promising. The rational design of such heterostructures requires synthesis routes that combine interfacial cleanliness, structural control, and real-time mechanistic insight. In this study, we report a solvent-free strategy for growing high-crystalline MoS2 nanoflakes on single-walled carbon nanotubes (SWCNTs) using an integrated chemical vapor deposition/molecular beam epitaxy (CVD/MBE) platform coupled with operando X-ray photoelectron spectroscopy. This setup enables continuous monitoring of nucleation and growth under ultra-high vacuum, and allows atomically sharp interfaces. We achieved uniform coverage of SWCNT sidewalls with MoS2 nanoflakes about 4-5 layers thick (~4 nm) and spanning areas exceeding 100 nm2. Operando XPS uncovers a stepwise growth pathway from sulfur adsorption on CNTs to Mo–S3 cluster formation, and the subsequent transformation into crystalline 2H-MoS2 domains. Complementary in-situ XPS validation confirms the high crystallinity, stoichiometry, and van der Waals interfacial coupling of the final heterostructure. The resulting heterostructures exhibit abundant exposed edge sites, strong interfacial coupling, and p-doping of SWCNTs without covalent disruption. This work establishes a versatile route for precision engineering of hybrid nanostructures while providing insights into their atomistic growth mechanisms. (10.1038/s41699-026-00699-w)
  DOI : 10.1038/s41699-026-00699-w
• Refractive indices of photochemical haze analogs for Solar System and exoplanet applications: A cross-laboratory comparative study between the PAMPRE and COSmIC experimental setups
  
  • Drant Thomas
  • Sciamma-O’brien Ella
  • Jovanovic Lora
  • Perrin Zoé
  • Maratrat Louis
  • Vettier Ludovic
  • Garcia-Caurel Enric
  • Brubach Jean-Blaise
  • Wooden Diane H
  • Roush Ted L
  • Ricketts Claire L
  • Rannou Pascal
  Astronomy & Astrophysics - A&A, EDP Sciences, 2026, 706, pp.A167. Previous observations of Titan, Pluto, and Solar System gas giants, along with recent observations of exoplanet atmospheres with the James Webb Space Telescope, have taught us that photochemical hazes are ubiquitous and form in a variety of temperature, gas composition, and irradiation environments. Despite their crucial role in understanding their impact on observations and on the planetary radiative budget, the refractive indices of these haze particles remain unknown and are strongly influenced by changes in gas-phase chemistry. In this study, we performed a cross-laboratory investigation to assess the effect of the experimental setup and gas composition on the refractive indices of Titan, Pluto, and exoplanet haze analogs. We report new data in a broad spectral range from UV to far-IR (up to 200 µm) for future use in climate models and retrieval frameworks. We compare the refractive indices of laboratory haze analogs produced from six different gas compositions, in which we varied the relative abundances N 2 /CH 4 and CH 4 /CO in the initial gas mixture, using the PAMPRE (LATMOS, France) and COSmIC (NASA Ames Research Center, USA) experimental setups. We observed strong variations in the k values in the spectral range from UV to near-IR between the different analogs, which are caused by both the experimental setup and changes in the gas N 2 /CH 4 ratio. We find that the gas N 2 /CH 4 ratio has a stronger influence on the haze refractive indices in the entire spectral range compared to the gas CH 4 /CO ratio. The experimental setup is the primary factor affecting the refractive indices, confirming that the gas residence time, irradiation, pressure, and gas temperature are important parameters influencing the composition of the solid analog. The higher n and k values in the UV-visible range, along with the stronger amine, alkene, aromatic, and/or hetero-aromatic signatures in the mid-IR for the COSmIC analogs, are consistent with a greater incorporation of nitrogen into the COSmIC solid analogs compared to the PAMPRE analogs, even at similar nitrogen abundances in the gas phase. Haze analogs produced in gas mixtures without nitrogen, similar to the stratospheres of Solar System gas giants and the H 2 -dominated atmospheres of sub-Neptunes, are generally more transparent with lower n values across the entire spectral range from UV to mid-IR and should therefore be carefully considered in climate and observational applications. The variations in IR absorption features between hazes produced with and without nitrogen could help constrain the presence of N 2 in exoplanet atmospheres. (10.1051/0004-6361/202555916)
  DOI : 10.1051/0004-6361/202555916
• Scalable fabrication of high-quality WS2 thin films via solution processing for NO2 sensing
  
  • Li Ran
  • Maina Elmehdi Ould
  • Dembélé Kassiogé
  • Denawi Adam Hassan
  • Vach Holger
  • Bouanis Fatima
  Materials Today Communications, Elsevier, 2026, 51, pp.114748. (10.1016/j.mtcomm.2026.114748)
  DOI : 10.1016/j.mtcomm.2026.114748
• Live-cell SICM imaging: An Introductory Guide for New Users
  
  • Papa Martina
  • Treussart François
  • Mothet Jean-Pierre
  • Güell Aleix G
  , 2026. High-resolution, minimally invasive imaging of live cells is essential for investigating cellular morphology and its dynamic changes. Among available approaches, Scanning Ion Conductance Microscopy (SICM) offers a unique combination of precise topographic imaging down to nanoscale with experimental conditions that preserve true livecell behavior. Here, we present a practical guide based on our own experience and experiments, intended to be a resource to help first-time SICM users, covering critical aspects from instrumentation, probe characterization, to cell preparation and morphometric data extraction and presentation, to accelerate their implementation, learning and to gain confidence in exploring live-cell structure and dynamics. (10.1021/acs.analchem.5c08201)
  DOI : 10.1021/acs.analchem.5c08201
• A Bayesian System with Neuron Clocks for Biosignal Classification
  
  • Li Zonglong
  • Calvet Laurie E
  , 2026. A compact Bayesian system for end-to-end inference that uses time-encoded probabilistic computing is presented. The architecture integrates (1) a neuron clocking scheme for timing sequential phases of the system, (2) a feature-extraction module based on rate-coding information with neuron circuits, (3) a circuit able to extract likelihoods from a probability distribution and then calculate Bayes' rule and (4) a race-to-threshold winner-take-all circuit that can drive downstream actuation circuits. All circuits were implemented and simulated at the transistor level in TSMC 130 nm CMOS using a 1.0 V supply. The system was benchmarked using a two-category sleep-stage classification task, and achieved an accuracy of 80.8%, which closely matches the 81.5% result of an equivalent inference in software. The complete architecture uses less than 150 transistors, making it suitable for ultra-lowpower edge biosignal processing.
• Tunable spin-crossover in 2D ruthenium metal–organic frameworks based on hexahydroxybenzene ligand
  
  • Denawi Adam Hassan
  Journal of Physics and Chemistry of Solids, Elsevier, 2026, 208, pp.113154. (10.1016/j.jpcs.2025.113154)
  DOI : 10.1016/j.jpcs.2025.113154