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With the advancement of three-dimensional electronic technologies, 3D betavoltaics consisting of a mixture of a semiconductor converter and a beta emitter have been investigated to increase output power by maximizing the beta absorption in the semiconductor. Semiconductor radiation robustness has typically been evaluated by monitoring electrical properties during the beta irradiation process over a long dwell time. To quickly and safely assess semiconductor candidates for betavoltaics without incorporating high-activity beta emitters, a custom-designed electron beam system as a beta source surrogate has been used. In this work, we report the change of electrical performance of planar 4H-SiC, planar Si, and 3D Si ridge p-i-n diodes irradiated by high-flux and high-fluence electrons. The 4H-SiC diodes were found to suffer 45% degradation to output power with 100 keV electron irradiation at a fluence of 1.3 × 1018 cm−2; however, the Si diodes showed no decrease in performance at the highest fluence of 100 keV electron irradiation of 7 × 1018 cm−2. This demonstrates that Si is more radiation hard than 4H-SiC for 147Pm-based betavoltaics, with an average beta energy of 62 keV.

Dust hazards are considered to be one of the technical challenges for future lunar exploration. In our past work a new dust mitigation technology was introduced utilizing an electron beam to remove dust particles from various surfaces. This technology was developed based on a patched charge model, which shows that the emission and re-absorption of electron beam induced secondary electrons inside microcavities between dust particles can lead to sufficiently large charges on the dust particles, causing their release from the surface due to strong repulsive forces. In this paper an improvement in the effectiveness of this technology is demonstrated with varying the beam incident angle on dust-covered sample surfaces by rotating the samples relative to the beam. Due to random arrangements of the microcavities, more of them will be exposed to the beam with various incident angles, thereby causing more dust release from the surface. The cleaning performance is tested against three samples: glass, spacesuit, and a photovoltaic (PV) panel. Lunar simulant (

International audience; The degradation of InGaAsN pin subcell under 1 MeV electrons irradiation was studied by characterizing solar cells and dilute nitride bulk layers before and after irradiation. Cells are measured to retain more than 94 % of their original photocurrent after 10 15 cm-2 1 MeV-electrons irradiation. Moreover, no significant degradation of the optoelectronic properties is observed after irradiation.

A deep dielectric charging model of a solar array drive assembly (SADA) under the coupling effect of electron irradiation and operating voltage is established based on the bipolar charge transport process. The distribution of space charge, potential and electric field in SADA are simulated and analyzed under three different operating conditions, i.e., flux model for internal charging (FLUMIC) spectrum electron irradiation acting alone; operating voltage acting alone; electron irradiation and operating voltage coupled. The effects of electron flux enhancement, electron direction, and operating voltage on charging properties are studied. Based on these investigations, discharge risk and location are pointed out. In the case of electrons incident from the end surface acting alone, much more space charge will accumulate than that from the columnar surface, and the maximum electric field will be above 108 V/m when the flux enhancement exceeds 100. When the operating voltage acts alone, the maximum electric field will not exceed 107 V/m as long as the operating voltage is below 8772 V. Under typical spectrum, the maximum electric field under coupling effect increases linearly as the operating voltage increases. When the electron flux enhancement increases to 100 and 1000, the electron irradiation dominates the deep charging characteristic. This provides theoretical guidance for the methods of discharge containment in SADAs.

The CdTe solar cell engineering is still lacking maximum achievable power conversion efficiency as predicted based upon the detailed balance. In device development, each constituent layer plays important role and to reduce open-circuit voltage loss, the reduction of back surface recombination is a promising approach. It could be made by introducing a wide-band gap ZnTe layer between the absorber CdTe layer and metal contact which can solve the issue of the Schottky barrier at the interface. The ZnTe layers also need optimization to the physical properties to implicate in CdTe-based device and therefore, the present work reports annealing and thickness evolution to ZnTe films to seek their feasibility as rear contact material where 200 nm and 300 nm thin ZnTe films are developed employing e-beam evaporation and subsequently annealed at 100 °C, 200 °C and 300 °C in air ambient followed by characterizations by amicable tools for exploration of relevant physical properties. Findings demonstrate that the film thickness and annealing temperature have considerably affected the physical properties of the developed films and the 200 nm ZnTe thin films annealed at 100 °C may be implicated as rear contact material in CdTe solar cell devices.

The ever-increasing space exploration enterprise calls for novel and high-quality radiation-resistant materials, among which nonlinear optical materials and devices are particularly scarce. Two-dimensional (2D) materials have shown promising potential, but the radiation effects on their nonlinear optical properties remain largely elusive. We previously fabricated 2D bismuthene for mode-locking sub-ns laser; herein, their space adaption was evaluated under a simulated space radiation environment. The as-synthesized thin layers of bismuthene exhibited strong third-order nonlinear optical responses extending into the near-infrared region. Remarkably, when exposed to 60Co γ-rays and electron irradiation, the bismuthene showed only slight degradation in saturable absorption behaviors that were critical for mode-locking in space. Ultrafast spectroscopy was applied to address the radiation effects and damage mechanisms that are difficult to understand by routine techniques. This work offers a new bottom-up approach for preparing 2D bismuthene, and the elucidation of its fundamental excited-state dynamics after radiation also provides a guideline to optimize the material for eventual space applications.

Healing of a hole in a carbon nanotube under electron irradiation in high-resolution transmission electron microscopy at room temperature is demonstrated using molecular dynamics simulations with t...

Thin film SnOx layer grown using e-beam technique under different oxygen pressure has a significant effect on its surface morphology. With an increase in oxygen pressure, grain size, and the average surface roughness of the film reduces. The grain size and average surface roughness of the SnOx film can significantly affect the reflection and absorption of light, which are essential for optoelectronic devices. Thus, proper control of oxygen pressure during SnOx thin film growth may result in the desirable tuning of SnOx thin film properties to be used in various optoelectronic devices, like sensors, photovoltaic cells, etc.

Two-dimensional (2D) bismuth is expected to yield exotic electrical properties for various nanoelectronics, despite the difficulty in large-area preparation and property tuning directly on a device substrate. This work reports electron beam (e-beam) evaporation of large-area 2D bismuth directly on SiO2/Si with an electrical conductivity of ∼105 S m-1 and a field effect carrier mobility of ∼235 cm2 V-1 s-1 at room temperature, comparable to those of the molecular beam epitaxy (MBE) counterparts with a similar thickness. Interestingly, the electrical conductivity of 2D bismuth changes when exposed to laser irradiation that possibly induced an increase of the defect concentration, indicating a potential photo-sensor application. The electrical response of 2D bismuth can be modified either by laser irradiation or by varying the layer thickness. Due to the dimension and surface state effects in 2D bismuth, the layer thickness has a strong influence on the carrier concentration and mobility. Inspiringly, a simultaneous increase of the electrical conductivity and the Seebeck coefficient was achieved in 2D bismuth, which is preferred for thermoelectric performance but rarely reported. Our results provided a more accessible platform than MBE to produce decent quality 2D bismuth and similar Xenes with tunable electrical properties for various nanoelectronics.

Fluorescent nanodiamonds containing negatively-charged nitrogen-vacancy (NV−) centers are promising for a wide range of applications, such as for sensing, as fluorescence biomarkers, or to hyperpolarize nuclear spins. NV− centers are formed from substitutional nitrogen (P1 centers) defects and vacancies in the diamond lattice. Maximizing the concentration of NVs is most beneficial, which justifies the search for methods with a high yield of conversion from P1 to NV−. We report here the characterization of surface cleaned fluorescent micro- and nanodiamonds, obtained by irradiation of commercial diamond powder with high-energy (10 MeV) electrons and simultaneous annealing at 800 ∘C. Using this technique and increasing the irradiation dose, we demonstrate the creation of NV− with up to 25% conversion yield. Finally, we monitor the creation of irradiation-induced spin-1 defects in microdiamond particles, which we associate with W16 and W33 centers, and investigate the effects of irradiation dose and particle size on the coherence time of NV−., acceptedVersion

To gain the target functionality of graphene for gas detection, nonfocused and large-scale compatible MeV electron beam irradiation on graphene with Ag patterns is innovatively adopted in air for chemical patterning of graphene. This strategy allows the metal-assisted site-specific oxidation of graphene to realize monolithically integrated graphene-chemically patterned graphene (CPG)-graphene homojunction-based gas sensors. The size-tunable CPG patterns can be mediated by regulating the size of Ag prepatterns. The impacts of highly energetic electron irradiation (HEEI) on graphene are summarized as follows: (i) the selective p-type doping and the defect generation of graphene by the HEEI-induced oxidation, (ii) the resistance of the homojunction devices manipulated by the HEEI dose, (iii) the band gap opening of graphene as well as the lowering of the Fermi level, (iv) the work function values for pristine graphene and CPG corresponding to 4.14 and 4.88 eV, respectively, and (v) graphene-CPG-graphene homojunction for NO2 gas, revealing an 839% enhanced gas response compared with that of the pristine graphene-based gas sensor.

In this paper, the detail study of electrical conductivity of single layer graphene (SLG) on silicon dioxide (SiO2)/Silicon substrate irradiated by high energy (MeV) electron is presented. The SLG samples prepared by Chemical Vapor Deposition (CVD) were irradiated by 50 kGy, 100 kGy and 200 kGy doses of electron radiation at energy voltage of 3 MeV. Current-Voltage (I-V) characteristics and conductivity of the pristine and irradiated graphene samples were measured and analysed using I-V measurement at room temperature. The non-linear I-V curves were clearly observed as the voltage reach to 2.0 V for non-irradiated and irradiated samples. This may be attributed to the non-uniform charges by high energy electron irradiation and poor metal contact of the sample. Hysteresis loop form at 2.0 V probably due to the to the charge trapping occurs at the interface of the graphene and SiO2. The reaction of high energy particles lead to creation of more carrier charges that contribute to the increment of conductivity compare to the small number of atom displacement of knock-on collisions with the nuclei of carbon atoms at higher dose. This study provides significant findings on the graphene electrical characteristics when irradiated with high energy (MeV) electron.

Calculations of the transmission factor, radiation, ionization and total losses for electrons with the energies of 10 MeV and 12 MeV that passing a layer of epoxy resin with a thickness of 5 mm with PEPA hardener (12 parts by weight) and with fillers of the iron and aluminum powders (30 parts by weigh) were conducted. It was established that the ionization losses of energy of fast electrons far exceed the radiation losses and increasing when imposing aluminum and iron powder fillers into the polymer matrix. In so doing, the transmission factor of the electron beam becomes smaller. Such electron energy losses for the epoxy composite layer with iron powder filler are greatest. This explains the high radiation resistance of the previously investigated n-Ge single crystals with such a protective epoxy coating layer to electron irradiation with energy of 10 MeV. A layer of epoxy resin ED-20 with aluminum and iron powder fillers may be promising material for creating relatively cheap, lightweight and technological protective coatings of elements of semiconductor electronics against the aggressive action of high-energy electron irradiation. The presented theoretical calculations can be used in the development and in modeling of such epoxy composite protective coatings of sensitive elements or semiconductor enclosures, which are in conditions of a high radiation.

We report the irradiation effects on rf reactive magnetron sputter deposited TiO2/Al2O3 hetero-structured thin films. These films are irradiated with 6 MeV electron beams by maintaining the dose ra...

Plasmonic sensors are commonly defined on two-dimensional (2D) surfaces with an enhanced electromagnetic field only near the surface, which requires precise positioning of the targeted molecules within hotspots. To address this challenge, we realize segmented nanocylinders that incorporate plasmonic (1-50 nm) gaps within three-dimensional (3D) nanostructures (nanocylinders) using electron irradiation triggered self-assembly. The 3D structures allow desired plasmonic patterns on their inner cylindrical walls forming the nanofluidic channels. The nanocylinders bridge nanoplasmonics and nanofluidics by achieving electromagnetic field enhancement and fluid confinement simultaneously. This hybrid system enables rapid diffusion of targeted species to the larger spatial hotspots in the 3D plasmonic structures, leading to enhanced interactions that contribute to a higher sensitivity. This concept has been demonstrated by characterizing an optical response of the 3D plasmonic nanostructures using surface-enhanced Raman spectroscopy (SERS), which shows enhancement over a 22 times higher intensity for hemoglobin fingerprints with nanocylinders compared to 2D nanostructures.

Diamond is a wide bandgap semiconducting material, and electron irradiation is a good modification method for diamond. When the diamond with a thickness of 0.1 mm is irradiated with MeV electrons, ...

SiC has currently attracted the interest of the scientific community for qubit applications. Despite the importance given to the properties of color centers in high-purity semi-insulating SiC, little is known on the electronic properties of defects in this material. In our study, we investigated the presence of electrically active levels in vanadium-doped substrates. Current mode deep level transient spectroscopy, carried out in the dark and under illumination, together with 1-D simulations showed the presence of two electrically active levels, one associated to a majority carrier trap and the other one to a minority carrier trap. The nature of the detected defects has been discussed in the light of the characterization performed on low-energy electron irradiated substrates and previous results found in the literature.

Forward and reverse current-voltage (I-V) characteristics of commercial rectifying Schottky diodes (SDs) based on silicon carbide (4H-SiC, base layer doping level 3·1015 cm-3) have been studied under irradiation with 0.9 MeV electrons and 15 MeV protons. The starting diodes were characterized by a barrier height of ~1.5 eV and nearly ideal forward and reverse I-V characteristics. It was found that, at doses exceeding the threshold dose Dth, the series differential resistance Rs of the diodes grows as Rs ~ Dm (m = 10-15) and shows no tendency toward saturation. Dth ≈7·1015 cm-2 under electron irradiation, and Dth ≈ 4·1013 cm-2 in the case of irradiation with protons. Heating to 200oC results in that Rs decreases with activation energy of ~1.1 eV and Rs is partly annealed-out with activation energy of ~0.7 eV. The starting Schottky diodes changes only slightly under irradiation, but, possibly, the irradiation leads to an over-compensation of the n-type layer and formation of an additional barrier in the form of a pn junction.

Subnanometer nanofabrication has been investigated, and electron beam processing has been found to be a suitable strategy to control nanoparticle organization over large areas. Organized nanostructures have demonstrated their potential for technological applications. Here, we focus on the processing of tungsten disulfide (WS2) due to its novelty and promising electronic properties for further development of functional devices. First, we summarize the theory of electron beam irradiation by surveying the dynamic behaviors observed during in situ experiments. In particular, the diverse structures with various numbers of layers derived from localized thinning produce considerable lateral heterointerfaces. The generation of the intriguing tungsten-rich cluster is also consistent with the mechanism of our atomic engineering experiments. These findings suggest a method for the electron beam processing of 2D materials and demonstrate the viability of atomic engineering using electron irradiation.

Minimizing the impact of radiation-induced degradation in dilute nitride based optoelectronic devices is crucial in its applications. The effects of 1-MeV electron irradiation (of 1 × 1014–1 × 1016 e/cm2 range) on undoped GaInNAs|GaAs single quantum-well (QW) structure has been studied by low-temperature photoluminescence (PL). PL spectra of GaInNAs|GaAs QW are measured before and after electron irradiation. The results show a slight enhancement of the PL intensity in relatively low electron fluence, and then subsequent deterioration of PL with the increase of cumulative electron fluences. The enhancement in PL intensity at low electron doses is explained by recombination-enhanced defect reaction model, and the degradation at high electron doses is explained by irradiation-induced defects in the lattice.

The electron beam (e-beam) in the scanning electron microscopy (SEM) provides an appealing mobile heating source for thermal metrology with spatial resolution of ∼1 nm, but the lack of systematic quantification of the e-beam heating power limits such application development. Here, we systemically study e-beam heating in LPCVD silicon nitride (SiNx) thin-films with thickness ranging from 200 to 500 nm from both experiments and complementary Monte Carlo simulations using the CASINO software package. There is good agreement about the thickness-dependent e-beam energy absorption of thin-film between modeling predictions and experiments. Using the absorption results, we then demonstrate adapting the e-beam as a quantitative heating source by measuring the thickness-dependent thermal conductivity of SiNx thin-films, with the results validated to within 7% by a separate Joule heating experiment. The results described here will open a new avenue for using SEM e-beams as a mobile heating source for advanced nanoscale thermal metrology development.

A uniform electron field is required for medical applications of electron linear accelerators (LINACs). Electron irradiation devices, including scattering foils and applicators for generating uniform electron fields, are widely used in medical LINACs. In this research, an electron scattering device consisting of scattering foils and applicators was designed for clinical application of a 9-MeV electron LINAC planned at the Dongnam Institute of Radiological & Medical Sciences. Monte Carlo simulations were performed to calculate the depth dose and the beam profile curves in a water phantom by using the EGSnrc Monte Carlo code.

Transparent conductive ZnO 50 nm/Ag 10 nm/SnO2 50 nm (ZAS) tri-layer films were deposited on glass substrates by magnetron sputtering, and then the surface was subjected to intense electron beam irradiation to investigate the effects of electron irradiation on the structural, optical, and electrical properties of the films. After deposition, the ZAS thin films were electron-irradiated for 10 minutes, with varying electron incident energies of 300, 600, and 900 eV. The films that were electron irradiated at 900 eV showed higher optical transmittance of 83.6% in the visible wavelength region, and lower resistivity, of 4.75 × 10-5 Ωcm, than the other films. From the observed electrical properties and optical band gap, it was concluded that the optical band gap increased with the incident electron energy up to 600 eV. The optical band gap increased from 4.12 to 4.23 eV, with carrier density increasing from 7.09 to 8.55 × 1021 cm−3. However, the film electron irradiated at 900 eV showed a decrease in optical band gap energy of 4.16 eV due to the decreased carrier density of 8.25 × 1021 cm−3. The figure of merit revealed that the ZAS thin films electron-irradiated at 900 eV had higher optical and electrical performance than the other films prepared in this study.

In the presented study, the performance improvement of Au/PTCDA/n-Si diodes was demonstrated with the help of pre-irradiation of PTCDA powders. The crystallographic analysis was carried out by X-ray diffraction method after the pre-irradiation of PTCDA powders. After the vacuum deposition of pre-irradiated (PI) and unirradiated (UI) PTCDA thin films, the Au/PTCDA/n-Si diodes were fabricated. The I-V, C-V, and G/omega-V characteristics were analyzed for Au/PTCDA/n-Si diodes with UI PTCDA as an interfacial layer (D1-pristine) and PI PTCDA with 30 kGy as an interfacial layer (D2). Radiation-induced effects on the produced diodes were investigated with parameters of the barrier height (phi(Bo)), series resistance (R-s), and the density of interface states (N-SS) and compared to the parameters of the pristine diode. It was observed that the electrical characteristics of Au/PTCDA/n-Si diodes, for D1 and D2, were highly influenced by the irradiation. Thus, the device performance could be improved with the pre-irradiation process. By modifying the HF-LF capacitance method to the UI-PI capacitance method, we successfully calculated the radiation-induced N-SS values without using C-V measurement at two different frequencies.

The electron transport layer (ETL) as an important part for high performing perovskite solar cells (PSCs), can transport photogenerated electrons while block holes. TiO2, as the usual ETL in the PSCs, may cause charge recombination in the device due to its poor electron conductivity. In order to improve the conductivity, we doped the Ce ions into TiO2 and used the e-beam method to fabricate the ETL layer. The doping of Ce could facilitate the charge transport and reduce the charge recombination, resulting in the increased power conversion efficiency (PCE) from 17.98% to 19.34%. And more, we also enhanced the stability of PSCs through the introduction of CsPbBr3 quantum dots (QDs) and Al2O3. As the ultraviolet (UV) to visible conversion layer, CsPbBr3 QDs were coated on the incident light side of the device to enhance the light stability of PSCs, while, as an encapsulation layer, the Al2O3 was put on the back side of the device to enhance the long-term stability of PSCs. As a result, the modified device can maintain 90% of initial efficiency after aging 4000 h in the ambient air.

Electron microscopy is crucial for imaging biological ultrastructure at nanometer resolution. However, electron irradiation also causes specimen damage, reflected in structural and chemical changes that can give rise to alternative signals. Here, luminescence induced by electron-beam irradiation is reported across a range of materials widely used in biological electron microscopy. Electron-induced luminescence is spectrally characterized in two epoxy (Epon, Durcupan) and one methacrylate resin (HM20) over a broad electron fluence range, from 10−4 to 103 mC cm−2, both with and without embedded biological samples. Electron-induced luminescence is pervasive in polymer resins, embedded biomaterial, and occurs even in fixed, whole cells in the absence of resin. Across media, similar patterns of intensity rise, spectral red-shifting, and bleaching upon increasing electron fluence are observed. Increased landing energies cause reduced scattering in the specimen shifting the luminescence profiles to higher fluences. Predictable and tunable electron-induced luminescence in natural and synthetic polymer media is advantageous for turning many polymers into luminescent nanostructures or to fluorescently visualize (micro)plastics. Furthermore, these findings provide perspective to direct electron-beam excitation approaches like cathodoluminescence that may be obscured by these nonspecific electron-induced signals.

The variation in applications of nanoparticles (NPs) comes from differences in their microstructures. This may be observed in the terms of variation in size, area fraction and even the morphology of the particles. It is mainly the size and topography of these particles which govern the mechanical, and optoelectronic properties and have a huge impact in Bio-medical engineering.

TN5nm HVM where EUVL was implemented on started in the middle of 2020, but EUV mask pattern inspection is still not ready in terms of fully satisfying customers' requirements. There are three tool candidates; optical, actinic, and e-beam inspection. The E-beam tools have high resolution and sensitivity, but have a low throughput. To better address market requirements, NuFlare has optimized its multi e-beam optics to inspect EUV masks, and apply D2DB method into the e-beam tool to achieve the throughput target. We describe the latest results of verification about main technologies to achieve throughput required for EUV mask inspection.

Monolayer (ML)-scale GaN/AlN multiple quantum well (MQW) structures for electron-beam-pumped ultraviolet (UV) emitters are grown on c-sapphire substrates by using plasma-assisted molecular beam epitaxy under controllable metal-rich conditions, which provides the spiral growth of densely packed atomically smooth hillocks without metal droplets. These structures have ML-stepped terrace-like surface topology in the entire QW thickness range from 0.75–7 ML and absence of stress at the well thickness below 2 ML. Satisfactory quantum confinement and mitigating the quantum-confined Stark effect in the stress-free MQW structures enable one to achieve the relatively bright UV cathodoluminescence with a narrow-line (~15 nm) in the sub-250-nm spectral range. The structures with many QWs (up to 400) exhibit the output optical power of ~1 W at 240 nm, when pumped by a standard thermionic-cathode (LaB6) electron gun at an electron energy of 20 keV and a current of 65 mA. This power is increased up to 11.8 W at an average excitation energy of 5 µJ per pulse, generated by the electron gun with a ferroelectric plasma cathode at an electron-beam energy of 12.5 keV and a current of 450 mA.

Electron microscopy (EM) is the most versatile tool for the study of matter at scales ranging from subatomic to visible. The high vacuum environment and the charged irradiation require careful stabilization of many specimens of interest. Biological samples are particularly sensitive due to their composition of light elements suspended in an aqueous medium. Early investigators developed techniques of embedding and staining with heavy metal salts for contrast enhancement. Indeed, the Nobel Prize in 1974 recognized Claude, de Duve, and Palade for establishment of the field of cell biology, largely due to their developments in separation and preservation of cellular components for electron microscopy. A decade later, cryogenic fixation was introduced. Vitrification of the water avoids the need for dehydration and provides an ideal matrix in which the organic macromolecules are suspended; the specimen represents a native state, suddenly frozen in time at temperatures below -150 °C. The low temperature maintains a low vapor pressure for the electron microscope, and the amorphous nature of the medium avoids diffraction contrast from crystalline ice. Such samples are extremely delicate, however, and cryo-EM imaging is a race for information in the face of ongoing damage by electron irradiation. Through this journey, cryo-EM enhanced the resolution scale from membranes to molecules and most recently to atoms. Cryo-EM pioneers, Dubochet, Frank, and Henderson, were awarded the Nobel Prize in 2017 for high resolution structure determination of biological macromolecules.A relatively untapped feature of cryo-EM is its preservation of composition. Nothing is added and nothing removed. Analytical spectroscopies based on electron energy loss or X-ray emission can be applied, but the very small interaction cross sections conflict with the weak exposures required to preserve sample integrity. To what extent can we interpret quantitatively the pixel intensities in images themselves? Conventional cryo-transmission electron microscopy (TEM) is limited in this respect, due to the strong dependence of the contrast transfer on defocus and the absence of contrast at low spatial frequencies.Inspiration comes largely from a different modality for cryo-tomography, using soft X-rays. Contrast depends on the difference in atomic absorption between carbon and oxygen in a region of the spectrum between their core level ionization energies, the so-called water window. Three dimensional (3D) reconstruction provides a map of the local X-ray absorption coefficient. The quantitative contrast enables the visualization of organic materials without stain and measurement of their concentration quantitatively. We asked, what aspects of the quantitative contrast might be transferred to cryo-electron microscopy?Compositional contrast is accessible in scanning transmission EM (STEM) via incoherent elastic scattering, which is sensitive to the atomic number Z. STEM can be regarded as a high energy, low angle diffraction measurement performed pixel by pixel with a weakly convergent beam. When coherent diffraction effects are absent, that is, in amorphous materials, a dark field signal measures quantitatively the flux scattered from the specimen integrated over the detector area. Learning to interpret these signals will open a new dimension in cryo-EM. This Account describes our efforts so far to introduce STEM for cryo-EM and tomography of biological specimens. We conclude with some thoughts on further developments.

Introduction. Currently, an interest in improving pin-structures continues to be the focus of attention of developers of electronic devices. Devices that use controlled pin-structures include: non-volatile memory, static voltage protection device, pin-diodes with adjustable characteristics, etc. However, insufficient attention is paid to the issue of controlling the characteristics of pin-structures by using discrete metallization on the surface of i-region.Aim. Investigation of the influence of discrete metallization of the surface of i-region on static and dynamic characteristics of pin-structure, defect compensation, and efficiency control of the pin-photodetector.Materials and methods. The pin-structure under study consisted of p + -boron-doped region; n + -phosphorusdoped region; i-phosphorus-doped region; semi-insulating substrate; metallization of the substrate; polysilicon control gate; and a silicon oxide dielectric layer. Two-dimensional numerical analysis of the potential distribution, of the concentration of free charge carriers and currents was performed in the Synopsys Sentaurus TCAD environment.Results. Two-dimensional analysis of discretely metallized pin-structures was performed. The stresses applied to the gates of i-region that compensated the influence of defects formed by electron irradiation were determined. Four pin-photodetector structures were modeled, in which the control gates were performed in the form of metal–dielectric–semiconductor structure. The possibility of increasing the sensitivity of the pinphotodetector by applying the corresponding potentials to the gates was demonstrated.Conclusion. An effect of discrete metallization of i-region of the pin-structure was investigated. A method for correcting of the characteristics of the irradiated pin-diode to the initial characteristics was proposed. It makes possible to use such diodes in electronics with high requirements for operating in areas with high radiation. The design of a high-sensitivity photodetector with control gates on the surface of i-region and with the structure of low alloy i-region split into two regions (p- and n–type conductivity) was proposed.

Graphene is of particular interest in utilizing it as a carbon-based radiation device due to its unique electronic properties. The understanding of radiation damage mechanism in graphene is crucial for applications in radiation harsh environments. In this paper, we investigate the influence of high energy (MeV) electron beam irradiation on structural and electrical properties of single layer graphene (SLG) prepared by Chemical Vapor Deposition (CVD) on SiO2/Si substrate using Raman Microscopy and Current-Voltage (I-V) measurement. The samples were irradiated at doses of 50 kGy, 100 kGy and 200 kGy with high energy voltage of 3 MeV. It was found that as irradiation dose increases to 100 kGy, the 2D bands and G bands shift to lower frequency energy and surprisingly no appearance of D band. As dose increases to 200 kGy, the G band shifts to higher frequency energy and 2D band shifts back to position similar with the pristine graphene as before irradiation. Only a small D band appear at 1349 cm−1 after 200 kGy of irradiation. This means that only small number of defects formed in SLG structure even after it is irradiated at higher electron energy (MeV), indicating stability of the SLG used in this study. I-V analysis shows non-monotonic behaviour of graphene which electrical conductance increase at 50 kGy, decrease at 100 kGy and increase significantly at 200 kGy. The major mechanism is probably related to the charge-transfer doping due to the high dose of electron irradiation and low defect scattering.

Electron irradiation causes atomic displacement damage and produces point defects in semiconductor materials. The formation and variation of defects determine the optical properties of semiconductors during the irradiation process. In this paper, Te-doped GaSb was irradiated by 1 MeV electrons, with fluence of 1 × 1015 electrons cm−2, and its optical properties investigated by temperature-dependent photoluminescence (PL) before and after irradiation. After irradiation, the peak position had a blue-shift and intensity was significantly enhanced. The carrier concentration increased from 4.14 × 1017 to 7.82 × 1017 cm−3 but mobility decreased from 2690 to 1780 cm2 V−1 s−1. These phenomena could be explained by the complex mechanism of defect decomposition, that is, the VGaGaSbTeSb defect decomposed into two independent VGaGaSb and TeSb defects. To verify this mechanism, undoped GaSb was irradiated under the same conditions and PL results indicated that electron irradiation had little effect on optical properties of undoped GaSb.

The Co/TiO2 multilayer thin films have been deposited by e-beam evaporation method on glass substrates in vacuum and annealed in air at 773 K for 1 h. The crystal structure, surface morphology, optical properties, electrical properties and magnetic properties of Co/TiO2 multilayer thin films have been systematically investigated. The results showed that the particle sizes were significantly reduced when the samples are annealed and the enlargement of particle size occurred when the samples thickness is increased. The spectroscopic analysis exhibited enhanced transmittance and higher optical band gap of annealed sample than the as-deposited one and it was decreased with sample thickness. The resistivity measurement confirmed resistivity decreament with temperature. Furthermore, by investigating the magnetic properties, room temperature ferromagnetism was observed.

In the present work, the kinetics of low-temperature annealing (400 °C) of 4H-SiC JBS diodes irradiated by electrons with an energy of 0.9 MeV and with a dose of 1E16 cm-2 was studied. The dynamics of changes in I-V, C-V characteristics, as well as DLTS spectra are shown. In the course of the work, a thermal cycling effect was discovered, i.e., effect of multiple rapid cooling to the temperature of liquid nitrogen and heating of the samples. As a result of thermal cycling, the barrier capacity increases and the on-resistance (Rs) decreases. In the DLTS spectrum, a level of - 0.38 eV appears, absent in the as-irradiated diodes.

The Total Skin Electron Beam (TSEB) irradiation is a radiotherapeutic technique that aims to provide the patient's skin surface with a more homogeneous dose, in order to treat cutaneous T-cell lymphomas, both for curative and palliative purposes. Electron irradiation penetrates a few millimeters into the skin, reaching the affected parts completely, without penetrating the internal organs. In vivo dosimetry has become an important role for the treatment of total skin irradiation within a rigorous quality assurance program that should be an integral part of the radiotherapy departments. The use of TLDs in vivo can identify variations in the prescribed dose because its measurement accuracy and great precision. The LiF:Mg,Ti is the most used TL material and widely studied in radiotherapy dosimetry due to near tissue-equivalence of the material, along with its overall reliability. The dosimeters of μLiF:Mg,Ti have been gaining considerable importance in the radiotherapy departments. These detectors allow measurements in vivo with great advantages due to their minimum dimensions of 1 × 1 × 1 mm3. This paper reports a comparative study of the TL responses of both materials to dose evaluation in TSEB treatments. The TL response of both materials in several TSEB parameter tests and in clinical application were evaluated, analyzing the dose distribution in a treatment simulation using AldersonRando anthropomorphic phantom. The results showed that the μLiF:Mg,Ti presented greater variation of the response in relation to LiF dosemeters in some parameters analyzed, due to the small dimensions and to evaluate doses absorbed in the surface over a large area in the treatment plan.

Degradation analysis of a quantum well-dilute nitride based multi-junction solar cell is presented using a 2D numerical device simulator: APSYS. By taking carrier removal effects into consideration, the proposed device exhibits strong electric field uniformity within the intrinsic region of the p-i-n middle cell. The electron traps are defined in the top InGaP and bottom InGaAsN base region considering 1 MeV electron irradiation in geostationary orbits. Considering thermionic emission, tunneling and SRH lifetime an effective lifetime value of 16.7 ps is considered in the middle MQW region. A record efficiency value of 38% and 44% is obtained at 1-sun and 500-sun AM0 spectrum respectively. The same efficiency value dropped by 4% by introducing a realistic SRV (1 × 104 cm s−1) and trap concentration values (1 × 1016 cm−3). Finally, we illustrate the influence of traps and lifetime on overall cell Jsc, Voc, η, and power density.

We introduce the controllable doping from hydrogen silsesquioxane (HSQ) to graphene by changing its electron-beam exposure dose. Using HSQ as the dopant, a fine-resolution electron-beam resist allows us to selectively dope graphene with an extremely high spatial resolution of a few nanometers. Therefore, we can design and demonstrate the single quantum dot (QD)-like transport in the graphene nanoribbon (GNR) with the opening of the energy gap. Moreover, we suggest a rough geometric design rule in which a relatively short and wide GNR is required for observing the single QD-like transport. We envisage that this method can be utilized for other materials and for other applications, such as p-n junctions and tunnel field-effect transistors.

This paper reports a comparative study of electron-beam evaporated ZnO, MgZnO, and CdZnO thin film based-gas sensor. At room temperature (RT), these semi-conductive thin films were deposited on Si/SiO2 substrate and an interdigitated pattern of chromium electrode deposited on these films. Device properties, such as structural, optical, and electrical, have been reported and analyzed. The sensors have been tested at different operating temperatures. At 250 °C, the sensor shows the best response for CdZnO thin films. We have obtained sensor response 4.86 with response time 15 sec for 100-PPM carbon mono oxide (CO) gas concentration for CdZnO thin film. Based on experimental results, Cd-doped ZnO has been found most suitable among these semiconducting metal oxides, when used as a CO gas sensor. A correlation between structural, optical, and electrical properties with these thin films has also been established.

In this article we have explored an effect of electron beam irradiation (EBI) on physical and nonlinear optical properties ZnO thin nano films. Nanostructured ZnO thin films were grown by low cost spray pyrolysis technique. The irradiation dosage has been fixed at 5 kGy, 10kGY, 15 kGy and 20 kGy. The structural investigation by Glancing angle X-Ray Diffractometer (GAXRD) confirms a polycrystalline phase of ZnO with wurtzite structure. The variation in the surface morphology upon EBI has been demonstrated using 2D and 3D Atomic force microscopy (AFM) images. Nanoscope software analysis quantifies the variation in surface roughness and average particle height upon EBI. The defect states created in the films upon irradiation experiments were investigated using UV–visible spectrophotometer, Room temperature Photoluminescence (RTPL), Raman and X-ray photoelectron spectroscopy (XPS). The increase in urbach tail validates the creation of localized defect states in the films The Gaussian fitting on RTPL spectra shows the quenching in the luminescent centers upon irradiation arised as result of recombination of vacancy defects. Phonon confinement model fitting on Raman spectra endorses that shift in the phonon modes observed on irradiation is due to spatial confinement of phonons. The elemental composition and impurity states of the EBI ZnO thin films were studied using XPS spectra. The shift in the binding energy of Zn and O elements infers the electron beam induced changes in the films. The electron beam irradiation has resulted in the increment of third order optical susceptibility χ(3) 3.5×10−4 esu to 8.13×10−3 esu due to the enhancement of electronic transition to different defect levels formed in the films and through local heating effects arising due to continuous wave (CW) laser illumination. The enhanced THG signal investigated using Nd:YAG laser at 1064 nm and 8 ns pulse width shows the promising features of EBI ZnO films for frequency tripling applications.

The nitrogen-vacancy (NV) centre is a fluorescent defect in diamond that is of critical importance for applications from ensemble sensing to biolabelling. Hence, understanding and optimising the creation of NV centres in diamond is vital for technological progress in these areas. We demonstrate that simultaneous electron irradiation and annealing of a high-pressure high-temperature diamond sample increases the NV centre creation efficiency from substitutional nitrogen defects by up to 117 % with respect to a sample where the processes are carried out consecutively, but using the same process parameters. This increase in fluorescence is supported by visible and infrared absorption spectroscopy experiments. Our results pave the way for a more efficient creation of NV centres in diamond as well as higher overall NV densities in the future.

Some preliminary results of experimental study (Raman spectroscopy, electron and optical microscopy, Auger spectroscopy) and theoretical discussion with computer modeling of few-layer graphene nanostructures, irradiated by SEM electron beams in the range 0.2 - 30 keV at room temperature with intensities varied in a wide interval on insulating (SiO2) and metallic (Ni foils) substrates are presented. The Raman spectroscopy data from irradiated specimens showed the obvious effect of substrate by all used beam energies. In the paper a new possible physical mechanism of subthreshold radiation structural damaging in a few-layer graphene and similar nanostructures is suggested.

We report a systematic electrical characterization of Mos 2 and PdSe 2 based FETs, with Ti/Au and Pd/Au contacts respectively, to investigate the effect of electron beam irradiation on the transistor channel current, threshold voltage, and contact resistance. We use a 10 keV electron beam inside a scanning electron microscope to irradiate the channel and/or the contact regions of the transistors and perform in-situ electrical measurements profiting of high precision metallic nanoprobes working as the source and the drain contacts. For Mos 2 based devices, we investigate the effect of electron irradiation either on the contact region or on the channel regions. Irradiation of the contact region causes an improvement of the transistor conduction by lowering the contact resistance, which we explain in terms of Schottky barrier reduction at the metal/Moxa interfaces. The irradiation with fluence below 100 e−/nm2 on Mos 2 channel region increases the device conductance and shifts the threshold voltage towards more negative voltages. For PdS2 based devices, electron beam irradiation with larger fluence up to 4200 e−/nm2 is detrimental to the conduction properties of the device, causing modification of the conduction from n-type to p-type, likely due to the accumulation of negative charges at the Si/SiO 2 interface. Moreover, charge carrier mobility is reduced by the formation of defects both in the PdSe2 nanosheets and at the Si/Si02 interface.

Demands on high quality x-ray imaging techniques are required for early detection of abnormal tissues and quality control of mass production in the field of medical and industrial applications.Moreover, smaller focal spot size (FSS) of x-ray sources have been developed for many decades but still their structure and operational scheme are complicated. To optimize electron beam trajectory, at least two types of focusing electrodes are needed. We demonstrate under 0.5 mm FSS of cold cathode x-ray source triode type e-beam module with vertically aligned carbon nanotubes (VA-CNTs) without any additional focusing electrodes. In addition, gate hole offset effects were investigated to FSS.The authors anticipate that our simple but sophisticated gate structure will be beneficial for high quality x-ray imaging and cost effective in terms of massive production of cold cathode x-ray generators.

The manufacturing process for flexible sensors requires a bendable substrate. Up to now, the fabrication of flexible sensor devices on flexible substrates has been highly challenging because of difficulties such as substrate alignment during deposition, patterning, and etching. We study a temporary bond–debond approach to overcome these issues. In this study, a metal foil was temporarily docked to a rigid carrier (i.e., glass sheet) for manufacturing an electronic device. We successfully implemented E-beam technology for bonding the metal foil with glass sheet. This approach allows the metal to bond with glass for relatively short time with required adhesion strength. To evaluate the applicability of this process method to electronic devices, we fabricated an optically resistive sensor based on an aluminum-doped zinc-oxide semiconductor material. After detaching the metal foil from the glass substrate, we investigated the electrical characteristics of the sensors.