POSTEROVÁ SEKCE A

This work investigates the synthesis of Ag/ZnO composite nanostructures by pulsed laser deposition (PLD) and laser annealing. Laser systems that generate nanosecond (15 ns) and picosecond (10 ps) pulses were used in the experiments. The nanosecond and picosecond laser regimes were employed to evaluate the effect of pulse duration on the morphology, structural characteristics, and optical properties of the deposited films. The laser nanostructuring enabled controlled formation of Ag nanoparticles, allowing precise tuning of their morphology and enhancement of the local electromagnetic field. The optical properties were studied with emphasis on the localized surface plasmon resonance (LSPR) of Ag nanoparticles and its influence on the photoluminescence of ZnO. Enhanced near-band-edge ultraviolet emission was observed, attributed to plasmon-exciton coupling and localized electromagnetic "hot spots" generated by the Ag nanoparticles. Numerical simulations of the electromagnetic field distribution quantified the dependence of “hot-spot” intensity on nanoparticle size, shape, and surrounding medium. The combined experimental and theoretical results demonstrate the potential of studied Ag/ZnO nanocomposites for plasmon-enhanced sensing and optoelectronic applications.
ACKNOWLEDGMENTS: The financial support from the Bulgarian Academy of Sciences (Project No. IC-CZ/03/2025-2026) within the framework of the bilateral agreement between BAS and the Czech Academy of Sciences is gratefully acknowledged.

Gallium Nitride (GaN) is extensively utilized in wireless telecommunications and radar systems due to its exceptional material and electrical characteristics, including a broad bandgap and elevated breakdown field. These characteristics make GaN more suitable for high-voltage and high-temperature applications compared to many other materials. We study the influence of the various geometrical and physical parameters of the transistor on the electrical characteristics based on two-dimensional numerical simulations in order to obtain a structure conducive to good operation. Our simulation results shows that the device designs based on GFP-HEMT AlGaN/GaN heterostructures is a promising candidate for high frequency and high power applications.

Vertically aligned ZnO nanorods were synthesized on FTO substrates using a two-step process combining spin coating and chemical bath deposition, followed by low-power hydrogen plasma treatment [1]. The influence of hydrogen plasma on the structural, optical, electrical, and photoelectrochemical properties of ZnO nanorods was systematically investigated. Structural and morphological analyses confirmed preservation of the hexagonal wurtzite phase and vertical nanorod alignment after plasma exposure, indicating that the treatment predominantly affects the near-surface region without compromising the overall structural integrity. Spectroscopic studies revealed redistribution and partial passivation of surface-related defect states. Photoluminescence measurements showed strong suppression of defect-related visible emission together with an approximately sevenfold enhancement of near-band-edge emission, demonstrating effective modification of defect-assisted recombination pathways.
Hydrogen plasma treatment significantly improved the electrical properties of ZnO nanorods. The sheet resistance decreased from 17.5 ± 2.0 to 0.30 ± 0.07 Ω sq⁻¹, accompanied by a substantial increase in carrier mobility. Mott-Schottky analysis revealed an increase in donor density from 2.85 × 10¹⁹ to 4.53 × 10¹⁹ cm⁻³. These changes resulted in enhanced photoelectrochemical activity, with the photocurrent density at 1.23 V vs RHE increasing from 160 to 250 μA cm⁻². Electrochemical impedance spectroscopy further demonstrated a decrease in charge-transfer resistance, confirming improved interfacial charge-transfer kinetics.
The combined results demonstrate that controlled hydrogen plasma treatment simultaneously passivates deep-level defect states and modifies shallow donor states in ZnO, leading to improved electrical conductivity, reduced recombination losses, and more efficient charge separation and transport. Hydrogen plasma processing therefore represents a promising surface defect-engineering strategy for optimizing ZnO nanorod photoanodes for photoelectrochemical applications.
REFERENCE: [1] A. Markhabayeva, R. Nemkayeva, Z. Kalkozova, Y. Yerlanuly, Z. Ongaibergenov, K. Karibayeva, L. Gritsenko, G. Suo, K. Abdullin, “Hydrogen Plasma-Driven Surface Defect Engineering of ZnO Nanorods: Correlating Electronic Structure and Photoelectrochemical Performance,” Langmuir, 2026, https://doi.org/10.1021/acs.langmuir.6c01230.

Conducting polymers have recently shown strong potential in analytical chemistry as alternative substrates for Surface-Enhanced Raman Scattering (SERS) spectroscopy. Among these, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) has shown promise for detecting organic dyes. However, its intrinsic SERS performance remains lower than that of traditional plasmonic nanomaterials, limiting its effectiveness for low-concentration analyte detection. To address this limitation, this study introduces a straightforward approach using a sandwich architecture that integrates sputter-deposited metallic base films with spin-coated, thermally cured PEDOT:PSS films. The metallic base layer acts as a "mirror" that, depending on its reflectivity, substantially modifies the SERS performance of the resulting coating. Among the tested metals (Al, Au, Ag, Pd, Cu, W, and V), aluminium was identified as optimal, enabling nearly an order-of-magnitude enhancement of the methylene blue SERS signal compared to PEDOT:PSS deposited on conventional Si wafers.
ACKNOWLEDGEMENTS: This work was supported by the Czech Science Foundation (grant no. 24-12197S).

The development of selective and sensitive gas sensors operating at or near room temperature is important for environmental monitoring with a focus on industrial safety and overall air-quality control. Among emerging sensing materials, bismuth sulfide (Bi₂S₃) has recently attracted considerable attention for low-temperature NO₂ detection due to its layered structure and strong interaction with oxidizing gas molecules affecting its surface charge-transfer processes and electrical conductivity. Formation of Bi2S3-semiconductor heterostructures can further amplify/enhance NO2 adsorption-induced electrical changes.
In this work, Bi₂S₃ is combined with hydrogen-terminated nanocrystalline diamond (H-NCD) aiming to develop heterostructure gas-sensing platforms with controllable electrical response and enhanced selectivity. The H-NCD surface provides a 2D hole-like conductive channel, while the Bi₂S₃/H-NCD interface introduces an additional pathway for interfacial charge redistribution. The electrical response of the heterostructures to NO₂ was investigated as a dependency of gas concentration, operating temperature (50 or 100°C), optical excitation and initial device resistance. At temperature of 50 °C, the response increased with NO₂ concentration (1-100 ppm) and peaked approximately at 275% for the devices with high initial resistance (1-10 kΩ), compared with values at 180% and 25% for devices with low initial resistance (below 1 kΩ). Repeated exposure to 100 ppm NO2 revealed that the initial resistance influences both the magnitude and temporal stability of the sensor response. Measurements performed under optical excitation additionally produced a distinct photo-induced effect resulting in negative photocurrent response.
The achieved results demonstrate that the sensing properties of Bi₂S₃/H-NCD heterostructure are affected by a) NO2 absorption on Bi₂S₃ surface; b) its morphology and surface chemistry; and c) the initial electrical state and charge-transport at the heterostructure interface. Engineering the Bi₂S₃/H-NCD interface and the initial device resistance therefore offers a promising route toward low-temperature selective NO₂ detection and potentially multifunctional sensing architectures compatible with chemiresistive and acoustic sensor platforms.

Aerosol jet printing (AJP) provides a maskless and digitally controlled route for the spatial deposition of nanodiamond particles, enabling the printed structures to serve as nucleation templates for subsequent chemical vapor deposition (CVD) of diamond. In this work, the AJP process was optimized for nanodiamond suspensions with nominal particle sizes of 5, 50, 100, and 150 nm printed on Si substrates. The influence of particle size, nozzle diameter, printing parameters, and printing multiplicity on the morphology and geometrical stability of the resulting structures was investigated. Both planar nucleation patterns and three-dimensional nanodiamond architectures were fabricated. By controlling the material deposition and toolpath, structures ranging from porous particle networks to dense and continuous features were obtained. The most reproducible three-dimensional printed structures were achieved using a 150 µm nozzle. Repeated printing allowed stacking of up to 200 deposited layers, resulting in features approximately 150 µm high and 200 µm wide. This demonstrates that AJP can extend nanodiamond patterning from conventional planar nucleation layers to bulk microstructures with controlled geometry and porosity.
The printed nanodiamond structures served directly as nucleation templates for selective-area diamond growth using microwave plasma-enhanced CVD. Both porous and dense core-shell architectures were successfully formed, whereas the conformally shaped shell consisted of either intrinsic or electrically conductive boron-doped diamond crystals. The developed approach combines additive nanodiamond patterning with CVD growth and provides a flexible route towards complex geometrically controlled diamond microstructures with tailored morphology, surface area, and opto-electrical properties with potential application in high-surface-area electrodes and sensor architectures.

Photoluminescence quantum yields exceeding 90 %, tuneable emission across the entire visible spectrum and short radiative carrier lifetimes make lead halide perovskite quantum dots (QDs) promising candidates for a wide variety of optoelectronic devices. Despite these advantages, their commercialization is hindered by poor stability arising from the dynamic binding of native ligands: oleic acid (OA) and oleylamine (OAm), which makes a repassivation process necessary to maintain QDs optical performance. Direct insight into the formation of these QDs allows for the optimization of repassivation parameters, helping to accelerate research progress.
In this work, we investigated the effect of OA and OAm ligands on CsPbX3 QDs during their formation via the hot injection method, using in situ photoluminescence (PL) to capture rapid changes such as defect formation and size variations. We identified a transient blue shift of the PL spectra at the onset of ice cooling, which is more pronounced when cooling from higher initial temperatures or under enhanced mixing dynamics. Under these conditions, slowed proton exchange between OA and OAm allows acidic surface etching of the QDs by OA. Subsequent in situ repassivation using a stronger binding ligand produces a pronounced redshift, driven by reduced native ligands influence and effective surface stabilization that repairs uncoordinated surface defects.
Transient blue shift at the start of ice cooling process provides a real-time indicator to optimize the timing of in situ QD repassivation, ensuring optimal optoelectronic performance and stability.
ACKNOWLEDGEMENTS: We would like to acknowledge the support of project 24-11652S (GACR).

Controlled surface modification is a vital approach in the development of materials with applications in sensing, electronics, and catalysis. Additive manufacturing techniques such as Fused Filament Fabrication enable rapid and cost-effective production of composite electrodes, including poly(lactic acid) with carbon additives (PLA-C). However, the printing process often leads to the development of layers of insulating polymer that hamper the charge percolation path, diminishing electrochemical performance. To overcome this, various post-processing methods such as laser ablation, chemical treatment, or plasma etching can be employed to modify surface layers of PLA-C. Argon plasma treatment enables physical etching of the surface, effectively removing insulating layers and exposing embedded conductive carbon structures. Moreover, such an approach is distinguished by low entry cost, in comparison to laser ablation, does not rely on toxic chemicals like dimethylformamide, and creates fairly uniform surface, unlike mechanical polishing.
In this work, we investigate the effects of argon plasma treatment, with the use of custom platform utilizing plasma torch, mounted on the modified 3D printer head. We compare obtained samples to other common post-processing methods of PLA-C electrodes. Electrochemical characterization demonstrates that plasma annealed PLA-C samples exhibit improved charge transfer kinetics and have enhanced current response in the presence of the redox pair compared to the untreated samples. Both, elaborated processing setup and optimized parameters allow for high reproducibility and controllability, while ensuring environmental sustainability and keeping costs low, which can be utilized for rapid manufacturing and prototyping workflows.
ACKNOWLEDGEMENTS: The authors acknowledge that the research was realized within project no: SKN/SP/658313/2026 and financially supported by Ministry of Science and Higher Education.

The luminescence properties of the macrocyclic Schiff-base compounds L1, S1 and S2 were investigated using UV-Vis absorption spectroscopy, fluorescence spectroscopy and time-resolved luminescence spectroscopy under synchrotron radiation excitation. The fluorescence spectra recorded in chloroform under excitation at 350 nm showed emission maxima in the range of 498-500 nm for the macrocyclic (2+2) compounds L1 and S2, whereas the macrocyclic (3+3) compound S1 exhibited an emission maximum at 549 nm. In the solid state, the compounds showed bathochromically shifted emission bands due to differences in intermolecular interactions, conformational changes and structural stiffness. The basic luminescent properties of the L1 and S2 powder samples were additionally studied using time-resolved luminescence spectroscopy under excitation by pulsed synchrotron radiation at 12 K. The emission spectra recorded under excitation at 180 and 260 nm showed dominant emission bands peaked at 598 and 535 nm, respectively. The photoluminescence excitation spectra, monitored at the corresponding emission maxima, were characterised by dominant bands at 7.56 eV for L1 and 7.60 eV for S2. These bands were assigned to the exciton creation energies associated with the emission centres of the macrocyclic compounds. The decay kinetics of L1 were close to single-exponential, with a decay time of 1.28 ns, whereas S2 showed strongly non-exponential decay behaviour, indicating a more complex luminescence mechanism. Three OLEDs with the ITO/PEDOT:PSS/emissive layer/Al structure were constructed using L1, S1 and S2 doped with PVK as the emissive layer. OLED-L1, OLED-S2 and OLED-S1 exhibited electroluminescence maxima at 543, 538 and 574 nm, respectively. The differences in the emission maximum values were attributed to variations in molecular structure, chirality, intermolecular interactions and the electronic effects of the substituents. OLED-S2, containing an electron-withdrawing bromo substituent, showed the highest maximum luminance of 219 cd m⁻² and the highest current efficiency of 0.25 cd A⁻¹. The obtained results confirm that the investigated macrocyclic compounds are promising emissive materials for green and yellow OLED applications.

Bismuth ferrite (BiFeO3, BFO) is a prominent multiferroic material widely investigated for photocatalytic, electronic, and energy storage applications. However, precise control over phase purity, particle dispersion, and morphology remains a significant challenge. Herein, we present a rapid, microwave-assisted solvothermal approach for the fabrication of BFO-MWCNT-COOH nanocomposites with varying functionalized carbon nanotube contents, as well as pristine BiFeO3.
The synthesis was carried out in N,N-dimethylformamide (DMF) using bismuth and iron nitrate precursors in the presence of urea, followed by microwave treatment at 150°C for 15 min. To evaluate crystallization behavior and phase evolution, the synthesized powders were calcined at 500°C for different durations (30, 60, and 90 min). The influence of MWCNT loading and thermal treatment parameters on the structural homogeneity, phase composition, and surface morphology was systematically investigated. The preliminary findings demonstrate that microwave-assisted synthesis combined with optimized annealing conditions provides effective control over BFO crystallization and its uniform distribution along the carbon nanotube scaffold, offering a promising route toward tailored multifunctional nanomaterials.

This study investigates the key role of nanoscale dimensions and interconnectivity in hollow three-dimensional graphitic structures (3D-GS) and their influence on electrochemical properties in lithium-ion batteries, as well as their impact on electrode degradation after cycling. 3D-GS with selected particle sizes (300 nm, 100 nm, and 10 nm) were synthesized using chemical vapor deposition (CVD). Optimization of the process parameters resulted in a reproducible number of graphene layers for all structure sizes. The materials were characterized using complementary microscopic, spectroscopic, and X-ray techniques. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) provided essential insights into the morphology and interconnectivity of the 3D-GS and were particularly effective in assessing their complex structure. Comprehensive electrochemical studies included cyclic voltammetry, impedance spectroscopy, and galvanostatic cycling tests. To better understand their electrochemical behavior, 3D-GS-based electrodes were characterized after 0 (initial state), 1, 2, 10, and 100 cycles using, among others, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy. The obtained results reveal the evolution of 3D-GS microstructure and structural stability during cycling, highlighting their potential for improving lithium-ion battery performance.
ACKNOWLEDGEMENT: This work was supported by the National Science Centre, Poland within the PRELUDIUM-20 project (No. 2021/41/N/ST5/03636) and by mobility project No. PAN-24-20 of the Polish Academy of Sciences and the Czech Academy of Sciences.

Designing graphene-based metal-free electrocatalysts is crucial due to their reduced costs, tunable molecular structures, superior electronic conductivity and substantial tolerance under fluctuating pH conditions. In this work, we have covalently functionalized fluoride graphite with n-octyl amine (OA), n-dodecyl amine (DDA), and n-octadecyl amine (ODA) via a facile nucleophilic substitution reaction to prepare three different N-alkylated fluorographene materials, OA-FGr, DDA-FGr, and ODA-FGr, respectively. Different characterization techniques have collectively confirmed their successful formation by providing information about their functionality, stacking, chemical interactions, morphology and textural properties. Moreover, electron paramagnetic resonance spectroscopy has been used to verify not only the functionalization but also the electrocatalytic properties. The synthesized materials have been utilized to prepare working electrodes to record linear sweep voltammetry (LSV) curves under acidic conditions (0.5 M H2SO4) and in an inert atmosphere at a scan rate of 5 mV s−1. ODA-FGr has demonstrated superior performance to its counterparts (OA-FGr and DDA-FGr), with an overpotential (η) of 530 mV at 10 mA cm−2 and a Tafel slope of 80 mV dec−1. Moreover, ODA-FGr has shown excellent durability, stability and reproducibility. Notably, the positive role of the alkyl chain length of amine molecules and their covalent functionalization is observed in improving HER performance and is found to be related to their amphiphilic nature and fluorine-to-nitrogen ratio. These results support our hypothesis about the role of longer alkyl chains, covalent bonding, and the amphiphilic nature of the materials in enhancing HER activity, and thus, they can be crucial in designing future electrocatalysts.

Nanographenes (NGs) are atomically precise fragments of graphene with tunable electronic and optical properties through structural modification and heteroatom incorporation [1]. Among these, hexabenzocoronene (HBC)-based bilayer [7]helicenes provide versatile platforms for investigating how structural and electronic modifications influence molecular properties. While heteroatoms such as nitrogen, oxygen, and sulfur have been incorporated into related π-extended frameworks [2], phosphorus-containing analogues remain comparatively unexplored. In particular, a central phosphole ring offers an opportunity to examine the influence of phosphorus within an otherwise closely related nanographene framework.
Here, we present a series of phosphorus-embedded bilayer nanographenes developed as a complementary extension of an existing library of HBC-based bilayer [7]helicenes. Three derivatives bearing phosphine oxide (P=O), sulfide (P=S), and selenide (P=Se) functionalities were prepared, providing a systematic platform to investigate the role of the phosphorus center and its chalcogenide environment.
The influence of these structural modifications was investigated using absorption and emission spectroscopy, cyclic voltammetry, chiroptical spectroscopy, and DFT calculations. The redox properties were found to depend on the oxidation state and chalcogenide coordination of phosphorus, while optical measurements revealed distinct changes in the absorption and emission profiles across the series. All three compounds exhibited clear electronic circular dichroism (ECD) and circularly polarized luminescence (CPL), with the nature of the chalcogenide influencing the dissymmetry factors (gabs and glum). These results establish phosphorus-embedded bilayer nanographenes as complementary members of the HBC-based helicene family and highlight the central phosphole environment as a structural parameter for tuning their electronic, optical, and chiroptical properties.
REFERENCES: [1] Borissov. A, et. al. Chem.Rev. 2022, 122, 565−788; [2] Reger, D., et al. Angew. Chem. Int. Ed. 2021, 60, 18073- 18081.

Molecular nanographenes are defined as structurally precise, two-dimensionally extended polycyclic systems representing one of the most dynamically developing classes of modern organic materials. Due to their structural rigidity and unique optoelectronic properties, nanographenes find broad application as functional chromophores and organic semiconductors in field-effect transistors, advanced photovoltaics, sensors, and bioimaging.[1]
A key strategy for refining their physicochemical parameters is doping the π-conjugated system with heteroatoms.[2] Introducing elements such as phosphorus into the aromatic system dramatically alters electron distribution, modulates HOMO-LUMO energy levels, and significantly enhances the luminescent properties and photostability.[3] Furthermore, the incorporation of a phosphorus atom enables diverse post-functionalization reactions, including oxidation, borylation, alkylation, and coordination to metals. These transformations allow for efficient tuning of key molecular properties, thereby tailoring the compounds for targeted applications.
Building on our synthetic expertise in introducing phosphorus heterocycles into aromatic systems,[4-6] we have prepared a phosphorus-containing nanographene based on a hexabenzocoronene scaffold (Scheme 1) and investigated its optical and physicochemical properties.
REFERENCES: [1] Martin, N. et al. J. Am. Chem. Soc. 2024, 146, 32222-32234; [2] Stępień et al., Chem. Rev. 2022, 122, 565-788; [3] Romero-Nieto, C. et al. Materials Today Chemistry 2021, 22, 100604-100628; [4] Beránek et al., Org. Lett. 2022, 24, 4756-4761; [5] Beránek et al., Adv. Synth. Catal. 2025, 367, e202401203; [6] Beránek et al., J. Org. Chem. 2026, 91, 6884-6894.

Nanomaterials play a vital role in the development of nanoscale devices, including oscillators, signaling systems, and drug delivery platforms. In this study, the van der Waals interactions between carbon nanotubes and molybdenum disulfide nanotubes are investigated using a continuum approximation based on the 6-12 Lennard-Jones potential. Two key aspects are examined: the suction energy governing the encapsulation of a carbon nanotube into a semi-infinite molybdenum disulfide nanotube, and the equilibrium radial offset of a carbon nanotube confined within the host nanotube.
Analytical expressions for the interaction energy and the corresponding axial force are derived and evaluated numerically for a range of armchair and zigzag configurations. The results indicate that encapsulation is energetically favorable when the inter-tube gap approaches the equilibrium van der Waals spacing, while insufficient radial clearance leads to dominant repulsive interactions that hinder insertion. Furthermore, the equilibrium radial offset decreases systematically as the inter-tube gap narrows, approaching a nearly concentric configuration at optimal spacing.
The proposed continuum model provides an efficient and physically transparent framework for predicting stable configurations of carbon nanotube-molybdenum disulfide nanotube systems, offering a valuable complement to computationally intensive atomistic simulations.

This paper deals with the geometric optimization of a needleless electrode for AC electrospinning technology to increase productivity. It focuses on a rod-like AC electrode suitable for laboratory-scale production of nanofibrous materials and the optimization of polymeric solutions, including materials for biomedical applications. The optimization is based on electric field analysis using the finite element method and CAD modeling for 3D printing of the final components. The work presents four distinct and novel approaches to increasing electrode productivity, developed by students as part of the international course Nanomaterials for Medical and Technical Applications under the Erasmus Blended Intensive Programme at the Technical University of Liberec. The designed electrodes were tested under real AC electrospinning conditions, evaluating both productivity and fiber morphology. A continuous electrospinning process was successfully confirmed for all four designs using a polyvinyl butyral solution as a model material. Furthermore, the electrodes were tested and evaluated by student team supervisors with polycaprolactone and polyamide solutions, demonstrating their applicability for processing both biodegradable and technical polymers. These results introduce new approaches to redesigning a well-established AC electrode type while highlighting an educational concept in nanofiber technology that provides hands-on experience for international students.

The negatively charged nickel vacancy centre (NiV−) in diamond is a promising spin qubit candidate with predicted inversion symmetry, large ground state spin-orbit splitting to limit phonon-induced decoherence, and emission in the near infrared range. Some of its optical properties overcome challenges associated with the well-known silicon-vacancy (SiV) defect in diamond. This study presents the excitation wavelength-dependent Raman and photoluminescence (PL) properties of the Ni-doped polycrystalline diamond films. Diamond films with thicknesses of 0.3, 0.5, and 2.8 um were deposited in a microwave plasma chemical vapor deposition (MWCVD) system on Si substrates. Nickel doping was realized using a Ni foam as a solid precursor. This resulted in the in-situ incorporation of Ni into the diamond crystals during the MWCVD growth process, forming NiV centres alongside SiV colour centres. The Raman and PL spectra of the samples were measured at room temperature using four different excitation wavelengths: 442, 488, 633 and 785 nm. The PL spectra confirmed the presence of the NiV centres at ~880 nm and SiV centres at ~736 nm. The surface morphology of the samples was characterized by scanning electron microscopy. The crystal size varied from 100 nm to 2 um depending on the thickness of the diamond film. The optical properties and the surface morphology of the samples were compared with those of reference samples grown under the same process conditions without Ni precursor. This work was supported by the Slovak Research and Development Agency (project # APVV-23-0361) and used large research infrastructure CzechNanolab (the MEYS project no. LM2023051). M.V. acknowledges support from the project IM-2023-87 funded by the Slovak Academy of Sciences via the programme IMPULZ 2023.

Ceramic piezoresistive pressure sensors are widely used in applications requiring mechanical robustness, chemical resistance, and operation over broad pressure ranges. Their performance is strongly influenced by the properties and geometry of the strain-sensitive resistive layer deposited on the ceramic diaphragm. In this work, nickel oxide (NiO) thin films are investigated as an alternative piezoresistive material for integration on monolithic ZrO₂ pressure-sensor diaphragms. NiO thin films are prepared by reactive DC magnetron sputtering from a metallic Ni target in an Ar/O₂ atmosphere. The influence of deposition conditions on film growth, electrical resistance, and suitability for the fabrication of strain-sensitive elements is investigated. Particular attention is given to the substantially higher electrical resistivity of NiO compared with conventional metallic sensing layers, requiring optimization of both the deposition process and resistor geometry. The NiO layers are characterized in terms of thickness, electrical properties, morphology, and piezoresistive response under mechanical loading. Based on the mechanical stress distribution in the ZrO₂ diaphragm, the position and geometry of the sensing elements are optimized for integration into a full Wheatstone bridge. The obtained results are compared with previously investigated sputtered metallic sensing layers. The study evaluates the potential of reactively sputtered NiO as a functional thin-film material for highly sensitive ceramic pressure sensors.

Machine learning offers new opportunities to connect semiconductor nanomaterial composition, thin-film fabrication, and device performance, but purely predictive relationships can be unstable across studies and may conflict with established materials knowledge. This work presents a reproducible framework combining domain-aware feature engineering, causal modelling, and explainable artificial intelligence for process-property analysis of halide-perovskite semiconductor thin films and solar-cell devices. The openly available Perovskite Database provides human-readable information on absorber composition, functional device layers, synthesis and processing procedures, device architecture, band gap, and photovoltaic performance. Regularized linear regression, decision trees, random forests, and gradient-boosted trees are compared for predicting power-conversion efficiency and related device metrics from selected material, process, and device-stack variables. Domain knowledge is incorporated through semantically grouped features, process-sequence constraints, and a strict separation of upstream fabrication conditions, intermediate material properties, and downstream performance quantities. An engineering-informed directed acyclic graph represents assumed dependencies among composition, deposition method, annealing conditions, layer structure, band gap, and device performance. SHAP-based explanations are complemented by resampling-based stability analysis and causal guardrails to prevent predictive feature importance from being interpreted directly as an intervention effect. The framework explicitly addresses missing data, study-to-study variation, and literature-derived selection effects. It provides an auditable basis for identifying reproducible process-property relationships and for supporting explainable, data-driven design of perovskite semiconductor nanomaterials and thin-film devices.

Layered transition metal tellurides represent an important class of materials for studying electronic transport phenomena associated with strong spin-orbit coupling and possible topological electronic states. In this work we report preliminary transport measurements on mechanically exfoliated telluride flakes prepared from bulk crystals and transferred onto Si/SiO₂ substrates. Electrical characterization was performed using the van der Pauw configuration, allowing determination of sheet resistance and Hall coefficient. The obtained Hall measurements demonstrate measurable carrier transport in exfoliated samples and confirm the feasibility of electrical characterization of thin telluride flakes. These initial results establish a basis for further magnetotransport investigations and for the fabrication of telluride-based heterostructures aimed at studying spin-orbit-driven transport phenomena.