Simple dynamic cell culture system reduces recording noise in microelectrode array recordings.

Microelectrode arrays (MEAs) have applications in drug discovery, toxicology, and basic research. They measure the electrophysiological response of tissue cultures to quantify changes upon exposure to biochemical stimuli. Unfortunately, manual addition of chemicals introduces significant noise in the recordings. Here, we report a simple-to-fabricate fluidic system that addresses this issue. We show that cell cultures can be successfully established in the fluidic compartment under continuous flow conditions and that the addition of chemicals introduces minimal noise in the recordings. This dynamic cell culture system represents an improvement over traditional tissue culture wells used in MEAs, facilitating electrophysiology measurements.

Silver Nano-Inks Synthesized with Biobased Polymers for High-Resolution Electrohydrodynamic Printing Toward In-Space Manufacturing.

Electrohydrodynamic (EHD) printing is an additive manufacturing technique capable of producing micro/nanoscale features by precisely jetting ink under an electric field. However, as a new technique compared to more conventional methods, commercially available inks designed and optimized for EHD are currently very limited. To address this challenge, a new silver nanoink platform was developed by synthesizing silver nanoparticles in situ with biobased polymer 2-hydroxyethyl cellulose (HEC). Typically used as a thickening agent, HEC is cost-effect, biocompatible, and versatile in developing inks that meet the rheology criteria for high-resolution EHD jetting. This approach significantly outperforms the traditional use of polyvinylpyrrolidone (PVP), enabling the stabilization of high solids content (>50 wt %) nanoinks for over 10 months with an HEC dosage 20 times lower than that required by PVP. The HEC-synthesized silver ink displays excellent electrical properties, yielding resistivities as low as 2.81 µΩ cm upon sintering, less than twice that of pure silver. Additionally, the capability to sinter at low temperatures (<200 °C) enables the use of this ink on polymer substrates for flexible devices. The synthesized nanoinks were also found to be capable of producing precise, high-resolution features by EHD printing with smooth lines narrower than 5 µm printed using a 100 µm nozzle. Additionally, a semiempirical model was developed to reveal the relationship between printing resolution, ink properties, and printing parameters, enabling precise printing control. Moreover, for the first time, the unique ability of EHD to achieve precise fabrication under microgravity was conclusively demonstrated through a parabolic flight test utilizing the HEC-based nanoinks. The study greatly expands the potential of printing thin films for the on-demand manufacturing of electronic devices in space.

Process Development of Aluminum Electroplating from an Ionic Liquid on 150 mm Wafer Level.

This paper focuses on the development of electroplating on 150 mm wafer level for microsystem technology applications from 1-Ethyl-3-methylimidazolium chloride (EMImCl) with Aluminumtrichloride (AlCl3). The deposition was carried out on 150 mm wafers with Au or Al seed layers deposited by physical vapor deposition (PVD). The electrodeposition was carried out using pattern plating. On the Au seed layer, bipolar pulse plating was applied. Compared to the Au seed layer, the electrodeposition on the Al seed layer was favorable, with lower current densities and pulsing frequencies. Utilizing the recurrent galvanic pulses and avoiding ionic liquid convection, inhomogeneities lower than 15% were achieved with a laboratory plating cell. One major aspect of this study was the removal of the native Al oxide prior to deposition. It was investigated on the chip and wafer levels using either current- or potential-controlled removal pulses. This process step was affected by the plasma treatment of the wafer, thus the surface free energy, prior to plating. It turned out that a higher surface free energy hindered proper oxide removal at a potential of 3 V. The theory of oxide breakdown based on electrostriction force via the electrical field was applied to discuss the findings and to derive conclusions for future plating experiments.

Rugged Island-Bridge Inorganic Electronics Mounted on Locally Strain-Isolated Substrates.

Various strain isolation strategies that combine rigid and stretchable regions for stretchable electronics were recently proposed, but the vulnerability of inorganic materials to mechanical stress has emerged as a major impediment to their performance. We report a strain-isolation system that combines heteropolymers with different elastic moduli (i.e., hybrid stretchable polymers) and utilize it to construct a rugged island-bridge inorganic electronics system. Two types of prepolymers were simultaneously cross-linked to form an interpenetrating polymer network at the rigid-stretchable interface, resulting in a hybrid stretchable polymer that exhibited efficient strain isolation and mechanical stability. The system, including stretchable micro-LEDs and microheaters, demonstrated consistent operation under external strain, suggesting that the rugged island-bridge inorganic electronics mounted on a locally strain-isolated substrate offer a promising solution for replacing conventional stretchable electronics, enabling devices with a variety of form factors.

Remote temperature sensing in microelectronics: optical thermometry using dual-center phosphors.

Remote thermal sensing has emerged as a temperature detection technique for tasks in which standard contact thermometers cannot be used due to environment or dimension limitations. One of such challenging tasks is the measurement of temperature in microelectronics. Here, optical thermometry using co-doped and mixed dual-center Gd2O3:Tb3+/Eu3+samples were realized. Ratiometric approach based on monitoring emission intensities of Tb3+(5D4-7F5) and Eu3+(5D0-7F2) transition provided sensing in the range of 30 °C-80 °C. Dispersion system type only slightly affected relative sensitivity, accuracy and precision. The applicability of phosphors synthesized to be utilized as remote optical thermometers for microelectronics has been proved with an example on a surface mount resistor and microcontroller.

Preparation and Properties of Low-Dielectric Polyimide Films Containing Tert-Butyl.

The design of high-performance polyimide (PI) films and understanding the relationship of the structure-dielectric property are of great significance in the field of the microelectronics industry, but are challenging. Herein, we describe the first work to construct a series of novel tert-butyl PI films (denoted as PI-1, PI-2, PI-3, and PI-4) based on a low-temperature polymerization strategy, which employed tetracarboxylic dianhydride (pyromellitic anhydride, 3,3',4,4'-biphenyl tetracarboxylic anhydride, 4,4'-diphenyl ether dianhydride, and 3,3',4,4'-benzophenone tetracarboxylic anhydride) and 4,4'-diamino-3,5-ditert butyl biphenyl ether as monomers. The results indicate that introducing tert-butyl branches in the main chain of PIs can enhance the free volume of the molecular chain and reduce the interaction between molecular chains of PI, resulting in a low dielectric constant. Particularly, the optimized PI-4 exhibits an excellent comprehensive performance with a high (5) wt% loss temperature (454 °C), tensile strength (117.40 MPa), and maximum hydrophobic angle (80.16°), and a low dielectric constant (2.90), which outperforms most of the results reported to date.

A Review of Recent Advances in Microneedle-Based Sensing within the Dermal ISF That Could Transform Medical Testing.

Interstitial fluid (ISF) has attracted extensive attention in an extremely wide range of areas due to its unique advantages, such as portability, high precision, comfortable operation, and superior stability. In recent years, the microneedle (MN) technique has been considered to be an excellent tool for extracting ISF because it is painless and noninvasive. Recent reports have shown that MN has good application prospects in ISF extraction. In this review, we provide comprehensive and in-depth insight into integrated MN devices for ISF detection, covering the basic structure as well as the fabrication of integrated MN devices and various applications in ISF extraction. Challenges and prospects are highlighted, with a discussion on how to transition such MN-integrated devices toward personalized healthcare monitoring systems.

Adhesion Characterization and Enhancement between Polyimide-Silica Composite and Nodulated Copper for Applications in Next-Generation Microelectronics.

As the need for high-speed electronics continues to rise rapidly, printed wiring board (PWB) requirements become ever-more demanding. A typical PWB is fabricated by bonding dielectric films such as polyimide to electrically conductive copper foil such as rolled annealed (RA) copper and is expected to become thinner, flexible, durable, and compatible with high-frequency 5G performance. Polyimide films inherently feature a higher coefficient of thermal expansion (CTE) than copper foils; this mismatch causes residual thermal stresses. To attenuate the mismatch, silica nanoparticles may be used to reduce the CTE of PI. A nodulated copper surface can be used to enhance the Cu/PI adhesion by additional bonding mechanisms that could include a type of mechanical bonding, which is a focus of this study. In this investigation, a 90° peel test was used to measure the peel strength in copper/polyimide/copper laminates containing nodulated copper and polyimide reinforced with 0, 20, and 40 wt % silica nanoparticles. The influence of silica nanoparticles on the peel strength was quantitatively evaluated. Laminates incorporating polyimide films lacking silica nanoparticles had a ∼3.75× higher peel strength compared with laminates reinforced with 40% silica. Their failure surfaces were analyzed by using scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), and X-ray photoelectron spectroscopy to identify the mode of failure and to understand bonding mechanisms. The key bonding mechanism, mechanical interlocking, was achieved when the polyimide surrounded or engulfed the copper nodules when the laminate was created. Post-testing failure surface analysis revealed the presence of copper on the polyimide side and polyimide on the copper side, indicating mixed mode failure. An analytical model was developed to determine the impact of applied pressure, temperature, and time on the polyimide penetration and mechanical interlocking around the copper nodules. The model was validated by measuring the peel strength on another set of specimens fabricated using increased temperature and pressure that showed a 3× increase in peel strength compared to lower temperature/pressure processing conditions. This enhanced adhesion resulted from the lower polymer material viscosity at higher temperatures, which fosters deeper and more complete penetration around the copper nodules during processing at higher pressures for longer durations. The methodology of combining peel testing, viscosity and CTE measurement, SEM/EDX, surface chemical analysis, and penetration depth calculation developed herein enables the calculation of the desired processing parameters to enhance functionality and improve adhesion.

Inversion for Thermal Properties with Frequency Domain Thermoreflectance.

3D integration of multiple microelectronic devices improves size, weight, and power while increasing the number of interconnections between components. One integration method involves the use of metal bump bonds to connect devices and components on a common interposer platform. Significant variations in the coefficient of thermal expansion in such systems lead to stresses that can cause thermomechanical and electrical failures. More advanced characterization and failure analysis techniques are necessary to assess the bond quality between components. Frequency domain thermoreflectance (FDTR) is a nondestructive, noncontact testing method used to determine thermal properties in a sample by fitting the phase lag between an applied heat flux and the surface temperature response. The typical use of FDTR data involves fitting for thermal properties in geometries with a high degree of symmetry. In this work, finite element method simulations are performed using high performance computing codes to facilitate the modeling of samples with arbitrary geometric complexity. A gradient-based optimization technique is also presented to determine unknown thermal properties in a discretized domain. Using experimental FDTR data from a GaN-diamond sample, thermal conductivity is then determined in an unknown layer to provide a spatial map of bond quality at various points in the sample.

Parametric Analysis of Indium Gallium Arsenide Wafer-based Thin Body (5 nm) Double-gate MOSFETs for Hybrid RF Applications.

INTRODUCTION: The electrical behavior of a high-performance Indium Gallium Arsenide (In- GaAs) wafer-based n-type Double-Gate (DG) MOSFET with a gate length (LG1= LG2) of 2 nm was analyzed. The relationship of channel length, gate length, top and bottom gate oxide layer thickness, a gate oxide material, and the rectangular wafer with upgraded structural characteristics and the parameters, such as switch current ratio (ION/IOFF) and transconductance (Gm) was analyzed for hybrid RF applications. METHODS: This work was carried out at 300 K utilizing a Non-Equilibrium Green Function (NEGF) mechanism for the proposed DG MOSFET architecture with La2O3 (EOT=1 nm) as gate dielectric oxide and source-drain device length (LSD) of 45 nm. It resulted in a maximum drain current (IDmax) of 4.52 mA, where the drain-source voltage (VDS) varied between 0 V and 0.5 V at the fixed gate to source voltage (VGS) = 0.5 V. The ON current(ION), leakage current (IOFF), and (ION/IOFF) switching current ratios of 1.56 mA, 8.49Í10-6 µA, and 18.3Í107 µA were obtained when the gate to source voltage (VGS) varied between 0 and 0.5 V at fixed drain-source voltage (VDS)=0.5V. RESULTS: The simulated result showed the values of maximum current density (Jmax), one and twodimensional electron density (N1D and N2D), electron mobility (µn), transconductance (Gm), and Subthreshold Slope (SS) are 52.4 µA/m2, 3.6Í107 cm-1, 11.36Í1012 cm-2, 1417 cm2V-1S-1, 3140 µS/µm, and 178 mV/dec, respectively. The Fermi-Dirac statistics were employed to limit the charge distribution of holes and electrons at a semiconductor-insulator interface. The flat-band voltage (VFB) of - 0.45 V for the fixed threshold voltage greatly impacted the breakdown voltage. The results were obtained by applying carriers to the channels with the (001) axis perpendicular to the gate oxide. The sub-band energy profile and electron density were well implemented and derived using the Non-Equilibrium Green's Function (NEGF) formalism. Further, a few advantages of the proposed heterostructure-based DG MOSFET structure over the other structures were observed. CONCLUSION: This proposed patent design, with a reduction in the leakage current characteristics, is mainly suitable for advanced Silicon-based solid-state CMOS devices, Microelectronics, Nanotechnologies, and future-generation device applications.

Determining Stress in Metallic Conducting Layers of Microelectronics Devices Using High Resolution Electron Backscatter Diffraction and Finite Element Analysis.

Delayed failure due to stress voiding is a concern with some aging microelectronics, as these voids can grow large enough to cause an open circuit. Local measurements of stress in the metallic layers are crucial to understanding and predicting this failure, but such measurements are complicated by the fact that exposing the aluminum conducting lines will relieve most of their stress. In this study, we instead mechanically thin the device substrate and measure distortions on the thinned surface using high resolution electron backscatter diffraction (HREBSD). These measurements are then related to the stresses in the metallic layers through elastic simulations. This study found that in legacy components that had no obvious voids, the stresses were comparable to the theoretical stresses at the time of manufacture (≈300 MPa). Distortion fields in the substrate were also determined around known voids, which may be directly compared to stress voiding models. The technique presented here for stress determination, HREBSD coupled with finite element analysis to infer subsurface stresses, is a valuable tool for assessing failure in layered microelectronics devices.

A Comprehensive Review of Bio-Inspired Optimization Algorithms Including Applications in Microelectronics and Nanophotonics.

The application of artificial intelligence in everyday life is becoming all-pervasive and unavoidable. Within that vast field, a special place belongs to biomimetic/bio-inspired algorithms for multiparameter optimization, which find their use in a large number of areas. Novel methods and advances are being published at an accelerated pace. Because of that, in spite of the fact that there are a lot of surveys and reviews in the field, they quickly become dated. Thus, it is of importance to keep pace with the current developments. In this review, we first consider a possible classification of bio-inspired multiparameter optimization methods because papers dedicated to that area are relatively scarce and often contradictory. We proceed by describing in some detail some more prominent approaches, as well as those most recently published. Finally, we consider the use of biomimetic algorithms in two related wide fields, namely microelectronics (including circuit design optimization) and nanophotonics (including inverse design of structures such as photonic crystals, nanoplasmonic configurations and metamaterials). We attempted to keep this broad survey self-contained so it can be of use not only to scholars in the related fields, but also to all those interested in the latest developments in this attractive area.

Thermal Management of Microelectronic Devices Using Nanofluid with Metal foam Heat Sink.

Microelectronic components are used in a variety of applications that range from processing units to smart devices. These components are prone to malfunctions at high temperatures exceeding 373 K in the form of heat dissipation. To resolve this issue, in microelectronic components, a cooling system is required. This issue can be better dealt with by using a combination of metal foam, heat sinks, and nanofluids. This study investigates the effect of using a rectangular-finned heat sink integrated with metal foam between the fins, and different water-based nanofluids as the working fluid for cooling purposes. A 3D numerical model of the metal foam with a BCC-unit cell structure is used. Various parameters are analyzed: temperature, pressure drop, overall heat transfer coefficient, Nusselt number, and flow rate. Fluid flows through the metal foam in a turbulent flow with a Reynold's number ranging from 2100 to 6500. The optimum fin height, thickness, spacing, and base thickness for the heat sink are analyzed, and for the metal foam, the material, porosity, and pore density are investigated. In addition, the volume fraction, nanoparticle material, and flow rate for the nanofluid is obtained. The results showed that the use of metal foam enhanced the thermal performance of the heat sink, and nanofluids provided better thermal management than pure water. For both cases, a higher Nusselt number, overall heat transfer coefficient, and better temperature reduction is achieved. CuO nanofluid and high-porosity low-pore-density metal foam provided the optimum results, namely a base temperature of 314 K, compared to 341 K, with a pressure drop of 130 Pa. A trade-off was achieved between the temperature reduction and pumping power, as higher concentrations of nanofluid provided better thermal management and resulted in a large pressure drop.

Investigations on Cylindrical Surrounding Double-Gate (CSDG) MOSFET using AlxGa1-xAs/InP: Pt with La2O3 oxide layer for fabrication.

INTRODUCTION: The Cylindrical Surrounding Double-Gate MOSFET has been designed using Aluminium Gallium Arsenide in its arbitrary alloy form alongside Indium Phosphide with Lanthanum Dioxide as a high-ƙ dielectric material. METHOD: The heterostructure based on the AlxGa1-xAs/InP: Pt has been used in the design and implementation of the MOSFET for RF applications. Platinum serves as the gate material, which has higher electronic immunity toward the Short Channel Effect and highlights semiconductor properties. The charge buildup is the main concern in the field of MOSFET design when two different materials are considered for fabrication. The usage of 2 Dimensional Electron Gas has been outstanding in recent years to help the electron buildup and charge carrier accumulation in the MOSFETs regime. Device simulation used for the smart integral systems is an electronic simulator that uses the physical robustness and the mathematical modeling of semiconductor heterostructures. In this research work, the fabrication method of Cylindrical Surrounding Double Gate MOSFET has been discussed and realized. The scaling down of the devices is essential to reduce the area of the chip and heat generation. By using these cylindrical structures, the area of contact with the circuit platform is reduced since the cylinder can be laid down horizontally. RESULT: The coulomb scattering rate is observed to be 18.3 % lower than the drain terminal when compared to the source terminal. Also, at x = 0.125 nm, the rate is 23.9 %, which makes it the lowest along the length of the channel; at x = 1 nm, the rate is 1.4 % lesser than that of the drain terminal. A 1.4 A/mm2 high current density had been achieved in the channel of the device, which is significantly larger than comparable transistors. CONCLUSION: The conventional transistor occupies a larger area than the proposed cylindrical structures transistor and is also efficient in RF applications.

Proof-of-Concept Vacuum Microelectronic NOR Gate Fabricated Using Microelectromechanical Systems and Carbon Nanotube Field Emitters.

This paper demonstrates a fully integrated vacuum microelectronic NOR logic gate fabricated using microfabricated polysilicon panels oriented perpendicular to the device substrate with integrated carbon nanotube (CNT) field emission cathodes. The vacuum microelectronic NOR logic gate consists of two parallel vacuum tetrodes fabricated using the polysilicon Multi-User MEMS Processes (polyMUMPs). Each tetrode of the vacuum microelectronic NOR gate demonstrated transistor-like performance but with a low transconductance of 7.6 × 10-9 S as current saturation was not achieved due to a coupling effect between the anode voltage and cathode current. With both tetrodes working in parallel, the NOR logic capabilities were demonstrated. However, the device exhibited asymmetric performance due to differences in the CNT emitter performance in each tetrode. Because vacuum microelectronic devices are attractive for use in high radiation environments, to test the radiation survivability of this device platform, we demonstrated the function of a simplified diode device structure during exposure to gamma radiation at a rate of 45.6 rad(Si)/second. These devices represent a proof-of-concept for a platform that can be used to build intricate vacuum microelectronic logic devices for use in high-radiation environments.

Modeling, Optimization, and Simulation of Nanomaterials-Based Organic Thin Film Transistor for Future Use in pH Sensing.

INTRODUCTION: Applications of Organic Thin Film Transistor (OTFT) range from flexible screens to disposable sensors, making them a prominent research issue in recent decades. A very accurate and exact pH sensing determination, including biosensors, is essential for these sensors. METHODS: In this present research work, authors have proposed a nanomaterial-based OTFT for future pH monitoring and other biosensing applications. This work presents a numerical model of a pH sensor based on Carbon Nano Tubes (CNTs). Sensing in harsh conditions may be possible with the CNTs due to their strong chemical and thermal resilience. This research work describes the numerical modeling of Bottom-Gate Bottom-Contact (BGBC) OTFTs with a Semiconducting Single-Walled Carbon Nanotube (s-SWCNT) and C60 fullerene blended active layer. RESULT: The design methodology of organic nanomaterial-based OTFTs has been presented with various parameter extraction precisely its electrical characteristics, modeled by adjusting the parameters of the basic semiconductor technology. For an active layer thickness of 200 nm, the drain current of the highest-performing s-SWCNT:C60 -based OTFT structure was around 4.25 A. CONCLUSION: This allows for an accurate representation of the device's electrical characteristics. Using Gold (Ag) Source/Drain (S/D) and back-gate electrodes as the medium for sensing, it has been realized how the thickness of the active layer impacts the performance of an OTFT for pH sensor applications.

Design and Analysis of Gallium Arsenide-Based Nanowire Using Coupled Non-Equilibrium Green Function for RF Hybrid Applications.

This research work uses sp3d5s* tight-binding models to design and analyze the structural properties of group IV and III-V oriented, rectangular Silicon (Si) and Gallium Arsenide (GaAs) Nanowires (NWs). The electrical characteristics of the NWs, which are shielded with Lanthanum Oxide (La2O3) material and the orientation with z [001] using the Non-Equilibrium Green Function (NEGF) method, have been analyzed. The electrical characteristics and the parameters for the multi-gate nanowires have been realized. A nanowire comprises a heavily doped n+ donor source and drains doping and n-donor doping at the channel. The specified nanowire has a gate length and channel length of 15 nm each, a source-drain device length LSD = 35 nm, with La2O3 as 1 nm (gate dielectric oxide) each on the top and bottom of the core material (Si/GaAs). The Gate-All-Around (GAA) Si NW is superior with a high (ION/IOFF ratio) of 1.06 × 109, and a low leakage current, or OFF current (IOFF), of 3.84 × 10-14 A. The measured values of the mid-channel conduction band energy (Ec) and charge carrier density (ρ) at VG = VD = 0.5 V are -0.309 eV and 6.24 × 1023 C/cm3, respectively. The nanowires with hydrostatic strain have been determined by electrostatic integrity and increased mobility, making them a leading solution for upcoming technological nodes. The transverse dimensions of the rectangular nanowires with similar energy levels are realized and comparisons between Si and GaAs NWs have been performed.

Design Optimization and Characterization with Fabrication of Nanomaterials-Based Photo Diode Cell for Subretinal Implant Application.

An ultrathin nano photodiode array fabricated in a flexible substrate can be an ideal therapeutic replacement for degenerated photoreceptor cells damaged by Age-related Macula Degeneration (AMD) and Retinitis Pigmentosa (RP), such as retinal infections. Silicon-based photodiode arrays have been attempted as artificial retinas. Considering the difficulties caused by hard silicon subretinal implants, researchers have diverted their attention towards organic photovoltaic cells-based subretinal implants. Indium-Tin Oxide (ITO) has been a favorite choice as an anode electrode. A mix of poly(3-hexylthiophene) and [6,6]-phenyl C61-butyric acid methyleste (P3HT: PCBM) has been utilized as an active layer in such nanomaterial-based subretinal implants. Though encouraging results have been obtained during the trial of such retinal implants, the need to replace ITO with a suitable transparent conductive electrode will be a suitable substitute. Further, conjugated polymers have been used as active layers in such photodiodes and have shown delamination in the retinal space over time despite their biocompatibility. This research attempted to fabricate and characterize Bulk Hetero Junction (BHJ) based Nano Photo Diode (NPD) utilizing Graphene-polyethylene terephthalate (G-PET)/semiconducting Single-Wall Carbon Nano Tubes (s-SWCNT): fullerene (C60) blend/aluminium (Al) structure to determine the issues in the development of subretinal prosthesis. An effective design approach adopted in this analysis has resulted in developing an NPD with an Efficiency of 10.1% in a non-ITO-driven NPD structure. Additionally, the results show that the efficiency can be further improved by increasing active layer thickness.

Thermal and Electrical Properties of Additively Manufactured Polymer-Boron Nitride Composite.

The efficiency of electronic microchip-based devices increases with advancements in technology, while their size decreases. This miniaturization leads to significant overheating of various electronic components, such as power transistors, processors, and power diodes, leading to a reduction in their lifespan and reliability. To address this issue, researchers are exploring the use of materials that offer efficient heat dissipation. One promising material is a polymer-boron nitride composite. This paper focuses on 3D printing using digital light processing of a model of a composite radiator with different boron nitride fillings. The measured absolute values of the thermal conductivity of such a composite in the temperature range of 3-300 K strongly depend on the concentration of boron nitride. Filling the photopolymer with boron nitride leads to a change in the behavior of the volt-current curves, which may be associated with the occurrence of percolation currents during the deposition of boron nitride. The ab initio calculations show the behavior and spatial orientation of BN flakes under the influence of an external electric field at the atomic level. These results demonstrate the potential use of photopolymer-based composite materials filled with boron nitride, which are manufactured using additive techniques, in modern electronics.

Advances in High-Energy-Resolution CdZnTe Linear Array Pixel Detectors with Fast and Low Noise Readout Electronics.

Radiation detectors based on Cadmium Zinc Telluride (CZT) compounds are becoming popular solutions thanks to their high detection efficiency, room temperature operation, and to their reliability in compact detection systems for medical, astrophysical, or industrial applications. However, despite a huge effort to improve the technological process, CZT detectors' full potential has not been completely exploited when both high spatial and energy resolution are required by the application, especially at low energies (<10 keV), limiting their application in energy-resolved photon counting (ERPC) systems. This gap can also be attributed to the lack of dedicated front-end electronics which can bring out the best in terms of detector spectroscopic performances. In this work, we present the latest results achieved in terms of energy resolution using SIRIO, a fast low-noise charge sensitive amplifier, and a linear-array pixel detector, based on boron oxide encapsulated vertical Bridgman-grown B-VB CZT crystals. The detector features a 0.25-mm pitch, a 1-mm thickness and is operated at a -700-V bias voltage. An equivalent noise charge of 39.2 el. r.m.s. (corresponding to 412 eV FWHM) was measured on the test pulser at 32 ns peaking time, leading to a raw resolution of 1.3% (782 eV FWHM) on the 59 keV line at room temperature (+20 °C) using an uncollimated 241Am, largely improving the current state of the art for CZT-based detection systems at such short peaking times, and achieving an optimum resolution of 0.97% (576 eV FWHM) at 1 µs peaking time. The measured energy resolution at the 122 keV line and with 1 µs peaking time of a 57Co raw uncollimated spectrum is 0.96% (1.17 keV). These activities are in the framework of an Italian collaboration on the development of energy-resolved X-ray scanners for material recycling, medical applications, and non-destructive testing in the food industry.