Soda lime silicate glass produced by the float process is among the materials with the largest use worldwide. The manufacturing process introduces an asymmetry in the glass sheets that causes well-known modifications in terms of properties between the so-called “air side” and “tin side”. Nevertheless, not much is known about the structural changes induced by the diffusing tin ions in the network. In the present work, we show that surprisingly, the short range of the tin side is akin to that of the bulk, while the network connectivity in the air side vicinity is enhanced with a larger concentration of bridging oxygens. This correlates with a partial depletion of modifiers from the air side as detected by secondary ion mass spectrometry. On the other hand, the incorporation of tin markedly changes the medium range. In fact, the tin side is characterized by: (i) longer correlation distances, (ii) a more homogeneous structure depicted by a more reduced splitting of the medium frequency Raman features into R and R c bands, (iii) a substantially lower amount of free volume, and (iv) a slight reduction in the average free volume size. Furthermore, the spontaneous hydration layer on the two surfaces is studied, and its effect on the free volume is discussed. These results provide new insight into the soda lime silicate glass structure and have various technological implications for processes like chemical tempering or phenomena like surface defects nucleation.

Photonic crystals (PhCs) are attractive for several applications due to their ability to confine light and enhance near-field interactions at low fabrication cost. Their optical response is characterized by the presence of a photonic bandgap (PBG). When combined with plasmonic nanostructures supporting localized surface plasmon resonances (LSPRs), they form metal-dielectric hybrids (MDHs) with enhanced and tunable optical functionalities. Here, we fabricate an MDH featuring gold nanocaps (NCs) on the surface of a colloidal PhC (opal) and characterize its optical response using static and femtosecond transient absorption (TA) spectroscopy. Static measurements reveal a broad plasmonic resonance, arising from the LSPRs sustained by the gold NCs. TA measurements uncover a strong interplay between the metal LSPRs and the opal PBG: the plasmon transient response is significantly enhanced by the PBG. For the first time, to the best of our knowledge, we demonstrate that this enhancement can be controlled by varying the excitation wavelength, owing to the slow-light regime, in agreement with the transfer matrix model predictions. Moreover, we show as proof-of-concept that the MDH ultrafast optical response is significantly modified by bacterial deposition, enabling ultrafast switching of the transient signal and underscoring the potential of these devices for biosensing applications.

In recent decades, nanodiamonds (NDs) have emerged as innovative nanotools for weak magnetic fields and small temperature variation sensing, especially in biological systems. At the basis of the use of NDs as quantum sensors are nitrogen-vacancy center lattice defects, whose electronic structures are influenced by the surrounding environment and can be probed by the optically detected magnetic resonance technique. Ideally, limiting the NDs' size as much as possible is important to ensure higher biocompatibility and provide higher spatial resolution. However, size reduction typically worsens the NDs' sensing properties. This study endeavors to obtain sub-100 nm NDs suitable to be used as quantum sensors. Thermal processing and surface oxidations were performed to purify NDs and control their surface chemistry and size. Ion irradiation techniques were also employed to increase the concentration of the nitrogen-vacancy centers. The impact of these processes was explored in terms of surface chemistry (diffuse reflectance infrared Fourier transform spectroscopy), structural and optical properties (Raman and photoluminescence spectroscopy), dimension variation (atomic force microscopy measurements), and optically detected magnetic resonance temperature sensitivity. Our results demonstrate how surface optimization and defect density enhancement can reduce the detrimental impact of size reduction, opening to the possibility of minimally invasive high-performance sensing of physical quantities in biological environments with nanoscale spatial resolution.

We report the excitation of optical Tamm states (OTS) in inverse opal (IO)- based three-dimensional photonic crystal on a flat metal substrate, validated through both numerical simulations and experimental observations. Large area, uniform Tamm inverse opal (Tamm-IO) structures were fabricated without the use of any corrosive chemicals. Upon infiltration of non-reactive solvents such as methanol and ethanol into the IO, a noticeable shift of the OTS, consistent with our simulations is observed, and the temporal dynamics of the same have been investigated. The experimentally obtained sensitivity is similar to 110 nm/RIU which is of the same order as the computed value, making the IO OTS to be an attractive sensing tool.

An experimental platform for laser-driven ion (sub-MeV) acceleration and potential applications was commissioned at the HiLASE laser facility. The auxiliary beam of the Bivoj laser system operating at a GW level peak power (~10 J in 5–10 ns) and 1–10 Hz repetition rate enabled a stable production of high-current ion beams of multiple species (Al, Ti, Fe, Si, Cu, and Sn). The produced laser–plasma ion sources were fully characterized against the laser intensity on the target (1013–1015 W/cm2) by varying the laser energy, focal spot size, and pulse duration. The versatility and tuneability of such high-repetition-rate laser–plasma ion sources are of potential interest for user applications. Such a statistically accurate study was facilitated by the large amount of data acquired at the high repetition rate (1–10 Hz) provided by the Bivoj laser system.

Hydrothermal treatments of soda-lime silicate glass cause a remarkable improvement in the resistance to flaw formation with an increase of the critical load to approximate to 1 kgf. This remarkable effect is achieved even if the reaction layer between the glass and water solution is well below 1 mu m. Positron Doppler broadening spectroscopy (DBS) reveals that the hydrothermal treatment causes a drop in the free volume of the glass network near the surface connected with the diffusion of molecular water whose presence was further confirmed by Fourier transformed infrared (FTIR) spectroscopy and secondary ion mass spectrometry (SIMS). Based on FTIR and SIMS, we also argue that the hydrothermal ion exchange is a double-step process: first H+ substitutes Na+ in the network, and following molecular water permeates the system. Moreover, we show that the presence of water in the network is fundamental in stabilizing the modified glass surface leading to toughening. Once molecular water is released, the network is quickly polymerized and becomes more brittle. Hydrothermal toughening is only a partially reversible process, once water is released it is not possible to reobtain the same properties with a second treatment. Finally, it is shown that air and tin side of the float glass perform differently as a result of different water diffusion kinetics related to dissimilarities in the network density. Hydrothermal treatments of soda-lime silicate glass allow for a substantial toughening of the material. Molecular water diffuses within the glass structure and leads to substantial densification of the network detected by antimatter probe. The water diffusion on the tin side of the float glass is slower leading to a reduced resistance to the crack formation. image

In this study, we present an all-solid-state electrochromic device (ECD) that eliminates the need for hard-to-obtain materials and conventional liquid/gel electrolytes. Using a cost-effective and industrially scalable spray coating technique, we developed an ECD containing a layer of zinc oxide nanorods (ZnOnano) synthesized via a simple solochemical route. The device configuration includes a preformed Al-coated glass substrate, acting as a counter electrode, within a glass/Al/ZnOnano/PEDOT:PSS architecture. The device exhibits reversible switching between light blue and dark blue states upon application of -1.2 V and +2.8 V, respectively, with a significant difference in transmittance between bleached and colored states in the visible-NIR spectrum, featuring a high coloration efficiency of 275.62 cm(2)/C at 600 nm. The response times required for both coloring and bleaching states were 9.92 s and 7.51 s, respectively, for a sample with an active area of 5.5 x 2.5 cm(2). Regarding the electrochemical stability of the ZnO-based ECD, the transmittance modulation reached around 8.01% at 600 nm after 12,800 s, following initial variations observed during the first 10 cycles. These results represent significant progress in electrochromic technology, offering a sustainable and efficient alternative to traditional ECDs. The use of economical fabrication techniques and the exclusion of critical materials highlight the potential for widespread industrial adoption of this novel ECD design.

A new development of radiation-resistant silicon sensors is presented. The new sensors exploit the Low-Gain Avalanche Diode (LGAD) technology, with internal multiplication of the charge carriers, in combination with thin substrates, intrinsically less affected by radiation. An innovative design of the gain implant typical of the LGADs has been developed and fabricated, employing the compensation of acceptor and donor dopants to reproduce the effective acceptor doping dose of standard LGAD sensors.At the end of 2022, the Fondazione Bruno Kessler (Italy) delivered the first batch of compensated LGAD sensors on 30μm thick p-type epitaxial substrates. Electrical and transient characterisation of the sensors has been performed before and after irradiation up to 5 ⋅1015 1 MeV equivalent n/cm2.The ultimate goal is to develop and produce compensated LGAD sensors that can efficiently operate above fluences of 1017 1 MeV equivalent n/cm2.

This study reports important analytical evidence of an unusual non-uniform element distribution in the super-ficial layers of glass matrices (from few nm up to 1 mu m). The unforeseen observation was made on silica-soda-lime glass mock-ups before and after their artificial ageing, using secondary ion mass spectrometry (SIMS) and X-ray photoelectron spectroscopy (XPS) surface analysis techniques. The analyses showed a marked non-homogeneous element distribution at the glass surface. The results indicated a very low concentration of Na at the surface up to a depth of around 500 nm below the surface, where its concentration increases reaching a plateau. In addition, the profile distribution of H in the first 200 nm of the pristine glass surface indicated a diffusion of hydrogen from the surrounding environment to the glass network. Additional modifications during the glass ageing process related to external factors (such as temperature and humidity) were also identified in relation to sodium atoms, with atoms on the glass surface showing a different chemical state from those in the bulk. This study confirms that glass composition as well as glass alteration are non-homogeneous locally sup-porting the importance of studying glass surface as region of interaction with surrounding environment.

Metal oxide semiconductor (MOS) gas sensors are widely used for gas detection. Typically, the hotplate element is the key component in MOS gas sensors which provide a proper and tunable operation temperature. However, the low power efficiency of the standard hotplates greatly limits the portable application of MOS gas sensors. The miniaturization of the hotplate geometry is one of the most effective methods used to reduce its power consumption. In this work, a new method is presented, combining electron beam lithography (EBL) and focused ion beam (FIB) technologies to obtain low power consumption. EBL is used to define the low-resolution section of the electrode, and FIB technology is utilized to pattern the high-resolution part. Different Au++ ion fluences in FIBs are tested in different milling strategies. The resulting devices are characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), and secondary ion mass spectrometry (SIMS). Furthermore, the electrical resistance of the hotplate is measured at different voltages, and the operational temperature is calculated based on the Pt temperature coefficient of resistance value. In addition, the thermal heater and electrical stability is studied at different temperatures for 110 h. Finally, the implementation of the fabricated hotplate in ZnO gas sensors is investigated using ethanol at 250 °C.

This study reports the first analytical evidence of an unexpected non-uniform element distribution in the superficial layers of glass matrices (from few nm up to 1 micron), hitherto unknown. The unforeseen observation was made while analysing silica-soda-lime glass mock-ups before and after their artificial ageing, using secondary ion mass spectrometry (SIMS) and X-ray photoelectron spectroscopy (XPS) surface analysis techniques. The analyses showed a marked, non-homogeneous element distribution at the glass surface and bulk. The results have indicated a very low concentration of Na at the surface up to a depth of around 500 nm in the glass, where its concentration increases, reaching a plateau. In addition, the profile distribution of H in the first 200 nm of the pristine glass surface indicated a diffusion of hydrogen from the surrounding environment to the glass network. Additional modifications during the glass ageing process related to external factors (such as temperature and humidity) have also been identified in relation to sodium atoms, with atoms on the glass surface observed being chemically different from those in the bulk.

Platelets are emerging as a promising source of blood biomarkers for several pathologies, including cancer. New automated techniques for easier manipulation of platelets in the context of lab-on-a-chips could be of great support for liquid biopsy. Here, several polymeric materials were investigated for their behavior in terms of adhesion and activation of human platelets. Polymeric materials were selected among the most used in microfabrication (PDMS, PMMA and COC) and commercial and home-made resins for 3D printing technology with the aim to identify the most suitable for the realization of microdevices for human platelets isolation and analysis. To visualize adherent platelets and their activation state scanning, electron microscopy was used, while confocal microscopy was used for evaluating platelets' features. In addition, atomic force microscopy was employed to further study platelets adherent to the polymeric materials. Polymers were divided in two main groups: the most prone to platelet adhesion and materials that cause few or no platelets to adhere. Therefore, different polymeric materials could be identified as suitable for the realization of microdevices aimed at capturing human platelets, while other materials could be employed for the fabrication of microdevices or parts of microdevices for the processing of platelets, without loss on surfaces during the process.

Highly porous Germanium surfaces with uniformly distributed columnar nanovoid structures are fabricated over a large area (wafer scale) by large fluence Sn+irradiation through a thin silicon nitride layer. The latter represents a one-step highly reproducible approach with no material loss to strongly increase photon harvesting into a semiconductor active layer by exploiting the moth-eye antireflection effect. The ion implantation through the nitride cap layer allows fabricating porous nanostructures with high aspect ratio, which can be tailored by varying ion fluence. By comparing the reflectivity of nanoporous Ge films with a flat reference we demonstrate a strong and omnidirectional reduction in the optical reflectivity by a factor of 96% in the selected spectral regions around 960 nm and by a factor of 67.1% averaged over the broad spectral range from 350 to 1800 nm. Such highly anti-reflective nanostructured Ge films prepared over large-areas with a self-organized maskless approach have the potential to impact real world applications aiming at energy harvesting.

In this work, the combined effect of negative tone photolithography and post-metallization annealing (PMA) on the electrical behavior of Al/Al2O3/p-Ge MOS structures are investigated. During photoresist development, the exposed upper part of the Al2O3 film weakens due to the reaction with the developer. Subsequent processes of Al deposition and PMA at 350 °C result in alumina thickness reduction. The gate electrode formation seems to involve at least three processes: (a) germanium substrate out-diffusion and accumulation at the top of the alumina layer that takes place during the alumina deposition, (b) alumina destabilization, and (c) germanium diffusion into the deposited Al metal and Al diffusion into the alumina. The overall effect is the reduction of the alumina thickness due to its partial consumption. It is shown that the germanium diffusion depends on the annealing duration, and not on the annealing ambient (inert or forming gas). Although PMA passivates interface traps near the valence band edge, the insulating properties of the stacks are degraded. This degradation appears as a low-level ac loss, attributed to a hopping current that flows through the Al2O3 layer. The results are discussed and compared to recently reported on Pt/Al2O3/p-Ge structures formed and treated under the same conditions.

A simple method for the determination of a Si p+/n junction depth is presented. The method is designed to delineate the specific junction due to its importance in the field of Si solar cells where cost effective and fast characterization techniques are necessary. It consists of the electrochemical transformation of the p+ Si to porous Si. The determination of the porous Si depth with the use of cross-sectional Scanning Electron Microscope (SEM) images provides a direct, fast and easy to implement measurement of the junction depth. In addition, through a simple 4-point probe electrical measurement of the sheet resistance, the average dopant concentration is determined, which allows the creation of an abrupt junction approximation of the p+/n junction. The method is shown to produce accurate results in two types of doping techniques, namely implantation and spin-on-doping and a range of junction depths between 200 nm and 1500 nm, as compared to the well-established secondary ion mass spectrometry (SIMS) technique.

Metal oxide thin films show promising resistive switching properties, making them materials of reference for the development of memristive devices. TiO2 is probably one of the most studied materials and is being synthesized using various techniques, each of them having specific optimizable characteristics. In this paper, we report on an innovative approach by combining the sol–gel and the pulsed microplasma cluster source (PMCS) methods, exploiting the low temperature and low cost of the former process and precise control over nanocristallinity of the latter. We show that this approach overcomes the reported limitations that each technique shows in fabricating memristive devices when independently used. A side-by-side comparison of the TiO2 thin films produced by the PMCS, sol–gel, and PMCS/sol–gel hybrid methods (HM) demonstrates an improvement of the memristive properties and a reduction of the electrical shorts in the TiO2 based devices.

Silicon carbide is a well-known material with high thermal, mechanical and chemical stability. These properties have allowed, over time, its wide use as an inert material to be employed as a substrate or support in different applications. In this work, we demonstrate that, under proper conditions, it is possible to activate the chemical reactivity of nanostructured SiC, which can be employed for chemoresistive purposes. With this aim, a commercial powder of SiC has been characterized from a morphological, structural and thermal point of view. Then, screen-printed thick films were obtained from SiC powder and thus tested as a functional material for chemoresistive gas sensors, in thermo-activation mode. The samples were exposed to 13 gases with important chemical differences. Analyses showed that SiC is an extremely selective functional material for the detection of sulphur dioxide (SO2) in concentrations within the ppm range. This interesting result was found at high working temperatures (600-800 degrees C), useful for harsh environments, and the measurements proved to be completely free from humidity negative interference. Thermo-gravimetric and X-ray photoelectron spectroscopy characterizations highlighted that the high selectivity of the SiC layer is promoted by the thermal formation of a SiC/SiOC core-shell, tunable by controlling temperature and humidity parameters. An interpretation of the gas sensing mechanism occurring between SO2 molecules and SiC/SiOC core-shell has been proposed. The unexpected chemical activity, identified for nanostructured SiC, can be exploited for the specific detection of SO2, since this gaseous compound plays an important role in air pollution, industrial processes and winemaking.

In this paper, we report on the radiation resistance of 50-micron thick LGAD detectors manufactured at the Fondazione Bruno Kessler employing several different doping combinations of the gain layer. LGAD detectors with gain layer doping of Boron, Boron low-diffusion, Gallium, Carbonated Boron and Carbonated Gallium have been designed and successfully produced. These sensors have been exposed to neutron fluences up to $\phi_n \sim 3 \cdot 10^{16}\; n/cm^2$ and to proton fluences up to $\phi_p \sim 9\cdot10^{15}\; p/cm^2$ to test their radiation resistance. The experimental results show that Gallium-doped LGADs are more heavily affected by initial acceptor removal than Boron-doped LGAD, while the presence of Carbon reduces initial acceptor removal both for Gallium and Boron doping. Boron low-diffusion shows a higher radiation resistance than that of standard Boron implant, indicating a dependence of the initial acceptor removal mechanism upon the implant width. This study also demonstrates that proton irradiation is at least twice more effective in producing initial acceptor removal, making proton irradiation far more damaging than neutron irradiation.

The choice of the optimum combination of materials for the absorber layers, electrodes, as well as interfacial layers is highly important to enhance further advances in the field of organic photovoltaics. Usually, these materials are assumed to be stable under the applied processing steps for the fabrication of the solar cells. Herein, organic tandem solar cells are examined with fluorine‐containing absorber layers consisting of the fluorinated polymer donor PTB7‐Th and the indacenodithiophene‐type small molecule acceptor O‐IDTBR and MoO 3 /Al/PFN‐Br as recombination layer. Although both subcells comprise the same low bandgap absorber materials, the tandem solar cells reveal high open‐circuit voltage values approaching 2 V. However, using a combination of scanning transmission electron microscopy nanoanalysis techniques and secondary ion mass spectrometry with depth profiling, an unexpected phenomenon is disclosed. It is found that significant amounts of fluorine are accumulated in the recombination layer region which originates very likely from alumina–aryl fluoride interactions responsible for a partial defluorination of the conjugated polymer in the absorber layer.

Germanium (Ge) surfaces have been irradiated with 26 keV gold (Au) ions at a constant fluence and at incidence angles varying from 0° to 85°. The evolution of the emerging nanostructures is studied by atomic force microscopy (AFM), scanning electron microscopy, x-ray photoelectron spectroscopy (XPS), and cross-sectional transmission electron microscopy. The obtained results are compared with findings reported in the literature. Periodic rippled patterns with the wave vector parallel to the projection of the ion beam direction onto the Ge surface develop between 30° and 45°. From 75° the morphology changes from parallel-mode ripples to parallel-mode terraces, and by further increasing the incidence angle the terraces coarsen and show a progressive break-up of the front facing the ion beam. No perpendicular-mode ripples or terraces have been observed. The analysis of the AFM height profiles and slope distributions shows in the 45°-85° range an angular dependence of the temporal scale for the onset of nonlinear processes. For incidence angles below 45°, the surface develops a sponge-like structure, which persists at higher incidence angles on the top and partially on the face of the facets facing the ion beam. The XPS and the energy-dispersive x-ray spectroscopy evidence the presence of Au nano-aggregates of different sizes for the different incidence angles. This study points out the peculiar behavior of Ge surfaces irradiated with medium-energy Au ions and warns about the differences to be faced when trying to build a universal framework for the description of semiconductor pattern evolution under ion-beam irradiation.