A series of Zn1-xMgxO thin films with the composition range x = 0.00-0.60 has been prepared by aerosol spray pyrolysis deposition on Si or quartz substrates. The morphology, composition, crystals structure, and optical properties of the prepared films were studied by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD), and optical spectroscopy. It was found that the morphology of films is not significantly different for films with different compositions, while the compositions correspond to those preset in the spray solutions, and all the films are of wurtzite structure up to the x value of 0.6. The optical bandgap of films was determined from the absorption spectra, and the dependence of the bandgap on the Mg content was compared with previously reported data. A photodetector with a design composed of two Zn1-xMgxO layers with different compositions was developed and characterized. It was found that the photodetector operates as injection photodiode with improved parameters as compared to a previous device with a single ZnMgO film prepared by spin coating.

A comparative study of the anodization processes occurring at the GaAs(111)A and GaAs(111)B surfaces exposed to electrochemical etching in neutral NaCl and acidic HNO3 aqueous electrolytes is performed in galvanostatic and potentiostatic anodization modes. Anodization in NaCl electrolytes was found to result in the formation of porous structures with porosity controlled either by current under the galvanostatic anodization, or by the potential under the potentiostatic anodization. Possibilities to produce multilayer porous structures are demonstrated. At the same time, one-step anodization in a HNO3 electrolyte is shown to lead to the formation of GaAs triangular shape nanowires with high aspect ratio (400 nm in diameter and 100 µm in length). The new data are compared to those previously obtained through anodizing GaAs(100) wafers in alkaline KOH electrolyte. An IR photodetector based on the GaAs nanowires is demonstrated.

A series of Zn1-xMgxO thin films with the composition range x = 0.00-0.40 has been prepared by sol-gel spin coating on Si substrates with a post-deposition thermal treatment in the temperature range of 400-650 degrees C. The morphology of the films was investigated by scanning electron microscopy and atomic force microscopy while their light emission properties were studied by photoluminescence spectroscopy under excitation at 325 nm. It was found that annealing at 500 degrees C leads to the production of macroscopically homogeneous wurtzite phase films, while thermal treatment at higher or lower temperature results in the degradation of the morphology, or in the formation of ZnO particles embedded into the ZnMgO matrix, respectively. Local compositional fluctuations leading to the formation of deep band tails in the gap were deduced from photoluminescence spectra. A model for the band tail distribution in the bandgap is proposed as a function of the alloy composition. Thin films were also prepared by aerosol spray pyrolysis deposition using the same sol-gel precursors for the purpose of comparison. The prepared films were tested for photodetector applications.

Zn1−xMgxO thin films were prepared by aerosol deposition and spin-coating method, using zinc acetate and magnesium acetate as precursors. The obtained films were investigated by scanning electron microscopy (SEM), electrical and photoelectrical characterization. SEM and energy dispersive x-ray (EDX) analysis has shown that the produced thin films are homogeneous in morphology and composition. The relaxation of photoconductivity under UV illumination was investigated in vacuum as a function of temperature. It was found that the thin films produced by spin-coating exhibit much higher photosensitivity and long duration relaxation of photoconductivity, in contrast to the films obtained by aerosol deposition. The investigation of photosensitivity in a wider spectral range demonstrated that the films are also sensitive to the visible and infrared irradiation.

The DArk Matter Particle Explorer (DAMPE) can detect electrons and photons from 5 GeV to 10 TeV and charged nuclei from a few tens of GeV to 100 TeV. The silicon–tungstentracker (STK), which is composed of 768 singled-sided silicon microstrip detectors, is one of four subdetectors in DAMPE providing photon conversion, track reconstruction, and charge identification for relativistic charged particles. This paper focuses on the charge identification performance of the STK detector. The charge response depends mainly on the incident angle and the impact position of the incoming particle. To improve the charge resolution, a reconstruction algorithm to correct for these parameters was tested during a test beam campaign conducted with a high-intensity ion beam at CERN. This algorithm was successfully applied to the ion test beam and the ion charge of Z=4∼10 and was successfully reconstructed for both normal and 9°incident beams.

In the frame of a project aimed at developing a new type of optical solar reflectors we present the scientific and technological issues addressed during irradiations of nano-hybrid coatings on polyimide films by using 20 keV electron beam from a modified use of Scanning Electron Microscope (SEM) and with ultraviolet (UV) dose equal to 300 space-equivalent Sun hours. Details of a new approach to use SEM for low energy electron irradiations and of a new UV irradiation setup are given.

A new CMS Tracker is under development for operation at the High Luminosity LHC from 2026 onwards. It includes an outer tracker based on dedicated modules that will reconstruct short track segments, called stubs, using spatially coincident clusters in two closely spaced silicon sensor layers. These modules allow the rejection of low transverse momentum track hits and reduce the data volume before transmission to the first level trigger. The inclusion of tracking information in the trigger decision is essential to limit the first level trigger accept rate. A customized front-end readout chip, the CMS Binary Chip (CBC), containing stub finding logic has been designed for this purpose. A prototype module, equipped with the CBC chip, has been constructed and operated for the first time in a 4 GeV/c positron beam at DESY. The behaviour of the stub finding was studied for different angles of beam incidence on a module, which allows an estimate of the sensitivity to transverse momentum within the future CMS detector. A sharp transverse momentum threshold around 2 GeV/c was demonstrated, which meets the requirement to reject a large fraction of low momentum tracks present in the LHC environment on-detector. This is the first realistic demonstration of a silicon tracking module that is able to select data, based on the particle's transverse momentum, for use in a first level trigger at the LHC . The results from this test are described here.

Recen% developed near W-photosensors are currently adopted in those applications where high sensitivity and good imaging capabilities are required, especially in fields such as astroparticle physics and medical imaging. An example of such applications is the camera of the Schwarzschild Couder Medium Size Telescope prototype (pSCT) which is in construction within the Cherenkov Telescope Array experiment. The camera consists of 177 photo-detection modules grouped into sectors of 25 modules, each based on matrixes of 64 6mm × 6mm pixels of Silicon Photomultipliers (SiPMs). Sensors produced by the Fondazione Bruno Kessler (FBK) in Italy are currently under investigation. Here we present a complete characterization of these highly sensitive near UV sensors, the assembly procedure and metrology results on several focal plane elements.

Methylammonium lead-halide perovskites are very promising for applications as solar light-harvesting materials. This paper presents a study on the methylammonium iodide and iodide-chloride perovskite films prepared by spin coating from a liquid precursor. The powder diffraction spectroscopy has detected 10 lattice plane reflections common to a perovskite of a tetragonal crystal structure. The calculated cell parameters are a = 8.85 Å and c = 12.60 Å. The preparation conditions and their impact on the crystallization process and film morphology are discussed. A red shift of photoluminescence bands at low temperatures was evidenced. A photoelectrical study of perovskite films has revealed their high sensibility to illumination, especially in the visible spectrum, which gives a hint on their applications in photovoltaics.

The Cherenkov Telescope Array (CTA) will be the next generation of ground-based observatory of very high energy gamma ray sources. The Italian Institute of Nuclear Physics (INFN) is involved in the R&D effort for the development of a possible solution for one of the Cherenkov photon camera designs, working on replacing the Hamamatsu MPPC S12642-0404PA-50 with more UV sensitive ones from Fondazione Bruno Kessler (FBK). INFN is currently developing the preamplifiers and the carrier boards for the SiPM chips that interface with the mechanics of the camera. To test the feasibility and the performance of SiPM cameras, a focal plane camera prototype module, upgraded with High Density NUV - SiPMs, produced by FBK, with a micro cell of 30 μm x 30 μm and 6 mm x 6 mm area, is being assembled. In this work, we describe the SiPM carrier boards, the assembly process and the qualification tests performed, before and after assembly, on the focal plane modules to qualify the procedures.

V. Gallo∗1, G. Ambrosi2, R. Asfandiyarov1, P. Azzarello1, P. Bernardini3,4, B. Bertucci2,5, A. Bolognini2,5, F. Cadoux1, M. Caprai2, I. De Mitri3,4, M. Domenjoz1, Y. Dong6, M. Duranti2,5, R. Fan6, M. Franco7, P. Fusco7,8, F. Gargano7, K. Gong6, D. Guo6, C. Husi1, M. Ionica2, N. Lacalamita7, D. La Marra1, F. Loparco7,8, G. Marsella3,4, M.N. Mazziotta7, M. Mongelli7, A. Nardinocchi2,5, L. Nicola1, G. Pelleriti1, W. Peng6, M. Pohl1, V. Postolache2, R. Qiao6, A. Surdo4, A. Tykhonov1, S. Vitillo1, H. Wang6, M. Weber1, D. Wu6, X. Wu1, F. Zhang6

The Italian Institute of Nuclear Physics is currently involved in the development of a prototype for a camera based on Silicon Photomultipliers (SiPMs) for the Cherenkov Telescope Array (CTA), a new generation of telescopes for ground{based gamma{ray astronomy. In recent years, SiPMs have proven to be highly suitable devices for applications where high sensitivity to low{intensity light and fast responses are required. Among their many advantages are their low operational voltage when compared with classical photomultiplier tubes, mechanical robustness, and increased photo{detection efficiency (PDE). Moreover, due to the possibility of operating them during bright moonlight, SiPMs can therefore considerably increase telescope duty cycle. Here we present a full characterization of a particular type of SiPM produced in Italy by the Fondazione Bruno Kessler, which is suitable for Cherenkov light detection in the Near-Ultraviolet (NUV). This device is a High{Density (HD) NUV SiPM, based on a micro cell of 40 μm × 40 μm and with an area of 6×6 mm2, providing low levels of dark noise and high PDE peaking in the NUV band. NUV-HD SiPMs will be arranged in a matrix of 8×8 single units to become part of the focal plane of the Schwarzschild-Couder Telescope prototype for CTA. An update on recent tests of the front-end electronics based on signal sampling with the TARGET-7 chip will be given as well.

The Italian Institute of Nuclear Physics (INFN) is involved in the development of a prototype for a SiPM-based camera for the Cherenkov Telescope Array (CTA), a new generation of telescopes for ground - based gamma ray astronomy. In this framework, an R&D program for the development of SiPMs suitable for Cherenkov light detection (Near-Ultraviolet SiPMs) has been carried out. The developed device is a High Density NUV-SiPM based on a micro cell of 30 μm × 30 μm and 6 mm × 6 mm area produced by Fondazione Bruno Kessler (FBK). A full characterisation of the single SiPM will be presented and compared with the old technology (NUV-SiPM) and with other SiPMs commercially available. The NUV-HD SiPM will be tested in the pSCT (Schwarzschild-Couder Telescope prototype) for CTA which is leading to a camera concept based on 8 × 8 NUV-HD SiPM module as detection unit. An update on recent tests on the detectors arranged in this matrix configuration and on the front-end electronics will be given.

The Cherenkov Telescope Array (CTA) Consortium is developing the new generation of ground observatories for the detection of ultra-high energy gamma-rays. The Italian Institute of Nuclear Physics (INFN) is participating to the RD\mbox{mm}^2$ area. Single SiPMs produced by FBK have been tested and their performances have been found to be suitable to equip the CTA cameras. Currently, INFN is developing the concept, mechanics and electronics for prototype modules made of 64 NUV-HD SiPMs intended to equip a possible update of the CTA Prototype Schwarzschild-Couder Telescope (pSCT) telescope. The performances of NUV-HD SiPMs and the design and tests of multi-SiPM modules are reviewed in this contribution.

The development of a new camera based on the use of Silicon Photomultipliers (SiPM) proposed for the Cherenkov Telescope Array (CTA), which represents a new generation of ground based very high energy gamma ray observatory, is one of the main items of the Italian Institute of Nuclear Physics (INFN). In the R&D framework a single channel electronic charge preamplifier has been developed to improve the performance of photon cameras equipped with High Density NUV – HD SiPM produced by Fondazione Bruno Kessler (FBK) with a micro cell of 30 μm x 30 μm and 6 mm x 6 mm total area. The single channel preamplifier will be used as basic component for a 16-channel electronic board prototype to test the 8 x 8 NUV – HD SiPM modules proposed to equip a pSCT (Schwarzschild-Couder Telescope prototype) camera. In this work the results of tests on the single channel preamplifier prototype to optimize the SiPM performances will be presented.

The high luminosity upgrade of the Large Hadron Collider, foreseen for 2026, necessitates the replacement of the CMS experiment’s silicon tracker. The innermost layer of the new pixel detector will be exposed to severe radiation, corresponding to a 1 MeV neutron equivalent fluence of up to \(\Phi _{eq} = 2 \times 10^{16}\) cm\(^{-2}\), and an ionising dose of \({\approx } 5\) MGy after an integrated luminosity of 3000 fb\(^{-1}\). Thin, planar silicon sensors are good candidates for this application, since the degradation of the signal produced by traversing particles is less severe than for thicker devices. In this paper, the results obtained from the characterisation of 100 and 200 \(\upmu \)m thick p-bulk pad diodes and strip sensors irradiated up to fluences of \(\Phi _{eq} = 1.3 \times 10^{16}\) cm\(^{-2}\) are shown.

The upgrade of the LHC to the High-Luminosity LHC (HL-LHC) is expected to increase the LHC design luminosity by an order of magnitude. This will require silicon tracking detectors with a significantly higher radiation hardness. The CMS Tracker Collaboration has conducted an irradiation and measurement campaign to identify suitable silicon sensor materials and strip designs for the future outer tracker at the CMS experiment. Based on these results, the collaboration has chosen to use n-in-p type silicon sensors and focus further investigations on the optimization of that sensor type. This paper describes the main measurement results and conclusions that motivated this decision.

On page 5497, M. Guix and co-workers demonstrate a novel light-driven microengine consisting of arrays of self-arranged titanium dioxide nanotubes with a conical inner diameter. Under exposure to UV irradiation, the microengine shows directed motion in solution, both in the presence and absence of hydrogen peroxide, and exhibits cargo capabilities, namely the controlled pick-up, transport and release of microscale particles.

Comparative analysis of transient photoconductivity in ZnO-based MSM structures and nanowires is performed in this paper. The measurements are carried out at room temperature in ambient air. The mechanisms of photoconductivity decay are discussed taking into account the range of measured relaxation times. It is found that the photoconductivity decay is determined by bulk effects in MSM structures, while it is governed by surface states and surface band bending effects in networks of nanowires.