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We investigated the capacitance of a forward-biased silicon pn diode using impedance spectroscopy. Despite extensive research spanning decades, no single model in the literature adequately describes the impedance behavior for bias up to the built-in voltage. By employing the 1N4007 diode as a case study, we analyzed the impedance over a wide frequency range, from 1 Hz to 1 MHz. Our analysis reveals that impedance can be effectively studied by combining two models. In both models, the depletion capacitance is assumed to be an ideal capacitor with a value independent of frequency. One model accounts for diffusion processes, while the other addresses interfacial effects, as well as potential and capacitance distributions across the junction. This approach offers valuable insights into the complex capacitance behavior of pn junctions as a function of the bias voltage. Measurements of depletion and diffusion capacitances, as well as of the diode transit time can be achieved from a set of impedance spectroscopy data. [ABSTRACT FROM AUTHOR]

The focus of the research is the laser bonding process that joins the laser diode silicon chip with the head gimbal assembly (HGA) slider in the hard disk drive. This study introduces a new technique for Au–Sn bonding using continuous wave (CW) laser transmission. The laser beam is transmitted through a quartz crystal to heat Alumina titanium carbide (AlTiC). The absorbed laser energy melts the Au–Sn substrates, effectively joining them. Key quality characteristics for ensuring bond quality and long-term reliability include shear strength, pitch angle, and gap of the bonded joint. A central composite rotatable design (CCRD) was used to investigate the influence of process parameters such as y-stage position, x-stage position, laser power, bonding time, and bonding force on quality characteristics. Multi-response surface optimization was then carried out to achieve optimal settings for all these characteristics simultaneously. The optimal process parameters were determined to be y-stage at − 0.0166°, X-stage at − 0.0660°, laser power at 3.8 W, time at 245 ms, and force at 13 kgf. Finally, empirical model validation was performed, resulting in slight differences between the predicted and actual values of shear strength, pitch angle, and gap, which were 2.00%, 3.70%, and 0.09%, respectively. [ABSTRACT FROM AUTHOR]

This work presents the effect of temperature change on the capacitance of silicon PIN diodes and the resulting change in performance of RF limiters at very high frequency (VHF). Device temperatures were varied between −25 ºC and 100 ºC, with small‐signal parameters (including device capacitance) extracted at regular temperature increments and bias voltages from −20 Vdc to +3 Vdc using a multi‐bias parameter extraction method. It was found that the junction capacitance of the four PIN diodes under investigation increases with temperature, as expected from carrier lifetime behaviour, while results also confirmed prior observations of an inverse relationship between forward‐biased series resistance and temperature. Devices were subsequently tested in two different limiter topologies through high‐power transient measurements. It was found that the combination of increased capacitance and decreased resistance with increasing temperature increases the transient spike leakage and decreases the flat leakage of a limiter. It was also concluded that, for VHF, an anti‐parallel topology provides the best performance over a wide range of temperatures. [ABSTRACT FROM AUTHOR]

Nearly four decades have passed since IBM scientists pioneered atomic force microscopy (AFM) by merging the principles of a scanning tunneling microscope with the features of a stylus profilometer. Today, electrical AFM modes are an indispensable asset within the semiconductor and nanotechnology industries, enabling the characterization and manipulation of electrical properties at the nanoscale. However, electrical AFM measurements suffer from reproducibility issues caused, for example, by surface contaminations, Joule heating, and hard‐to‐minimize tip drift and tilt. Using as experimental system nanoscale Schottky diodes assembled on oxide‐free silicon crystals of precisely defined surface chemistry, it is revealed that voltage‐dependent adhesion forces lead to significant rotation of the AFM platinum tip. The electrostatics‐driven tip rotation causes a strain gradient on the silicon surface, which induces a flexoelectric reverse bias term. This directional flexoelectric internal‐bias term adds to the external (instrumental) bias, causing both an increased diode leakage as well as a shift of the diode knee voltage to larger forward biases. These findings will aid the design and characterization of silicon‐based devices, especially those that are deliberately operated under large strain or shear, such as in emerging energy harvesting technologies including Schottky‐based triboelectric nanogenerators (TENGs). [ABSTRACT FROM AUTHOR]

For the first time, this work reports the fabrication of a p+-i-n + diode with a magnetic Mn-doped Ge quantum embedded in its intrinsic layer for photodetection and photovoltaic applications. The diode with Mn-doped Ge quantum dots is epitaxied by an ultra-high vacuum molecular beam epitaxy (UHV-MBE) reactor on a silicon substrate. Using atomic force microscopy and a superconducting quantum interference device to study the shape and magnetic properties of the Mn-doped Ge QDs revealed that they are uniform, dense, and ferromagnetic. The new p+-i-n + photodiode has a high rectification ratio of > 100 at a bias voltage of Vb = ± 1 V, a high breakdown voltage of 12 V, an ideality factor of n = 1.86, a Schottky barrier height of ϕB = 0.72 eV, and a broad spectral response in the visible with a high photocurrent/dark ratio of about 100. These original results pave the way for the real integration of magnetic Mn-doped Ge quantum dots in advanced optoelectronic and spintronic devices. [ABSTRACT FROM AUTHOR]

In the paper results of the operation and efficiency of a DC-DC resonant converter with a switched capacitor topology, equipped with GaN transistors and SiC diodes are presented. Investigated problems are related to the optimization of the DC-DC power electronic converter in order to achieve miniaturization, a simplified design, and high efficiency. The proposed system operates at a high frequency with low switching losses. The proposed design helps to achieve uniform heating of the transistors and diodes, as demonstrated by the results of the thermal imaging measurements. The GaN transistors are integrated into one package with dedicated gate drivers and used to simplify the circuitry of drivers and increase the power density factor of the proposed device. In the high-frequency design presented in the paper, the converter is implemented without electrolytic capacitors. The results included in the paper contain waveforms recorded in the power circuit at ZVS operation when switching on the transistors. It occurs when the system operates above the frequency of current oscillations in the resonant circuit of the switched capacitor. Efficiency characteristics and a voltage gain curve of the converter versus its output power are presented as well. The results of efficiency and quality of waveforms are important because they facilitate characterizing the tested system for implementation using WBG devices. The use of integrated GaN modules to minimize elements in the physical system is also unique to this model and it allows for very short dead-time use, and operation in ZVS mode at low reverse-conduction losses. [ABSTRACT FROM AUTHOR]

The in-vessel silicon diode arrays that are used for soft x-ray detection in many tokamaks are sensitive to neutron damage, making them unsuitable for burning plasma devices such as SPARC. In such a device, the silicon diodes would need to be placed far from the plasma—limiting their field of view—or an alternative detector could be used. Here, we present the design of a camera containing an array of chemical vapor deposition single-crystal diamonds, which will be placed in the upper and lower port plugs of the SPARC tokamak with a large enough view of the poloidal cross section to enable tomographic inversion. The camera design presented here is optimized to provide a wide field of view of the poloidal cross section. Simulated plasma conditions are used to estimate the x-ray signal that this detector array will receive and to fine-tune the camera placement within the tokamak. [ABSTRACT FROM AUTHOR]

Technological advancements have made it possible to harness the power of renewable energy sources. The efficiency of power electronic devices has increased to almost 98%. In order to reduce the risks of failure and maintain the operation of photovoltaic (PV)-based energy converters, reliable devices are needed. Due to the increasing number of wide-bandgap silicon in electronic converters, the need for more efficient and reliable devices has become more prevalent. However, the cost of these devices is a major issue. Hence, in this work extensive analysis of hybrid silicon (Si)-IGBT and silicon carbide (SiC) antiparallel Diode (H-IGBT/Diode) based PV inverter is proposed to improve the lifetime (Bx). A reliability oriented lifetime assessment is performed on a test case of single stage three kilowatt photovoltaic inverter with 600 V/30 A hybrid switch. Long term mission profile for one year is considered for evaluation at B. V. Raju Institute of Technology (BVRIT), Telangana, India. Finally, B10 lifetime is calculated, comparison analysis is presented between conventional Si-IGBT and proposed Si-SiC H-IGBT/Diode. The results of the study revealed that the H-IGBT exhibited a significant increase in PV inverter reliability. [ABSTRACT FROM AUTHOR]

Radiation-hardness of silicon (Si) has been the subject of interest due to the damage of the material-based detectors during and after operation. In this work, the effects of 4 MeV proton-irradiation on the electrical properties of devices fabricated on undoped and Fe-doped p-Si were investigated using current-voltage (I-V) and capacitance-voltage (C-V) techniques. A decrease in current and capacitance is less pronounced and the conduction mechanism remains unchanged on Fe-doped p-Si diode after proton-irradiation. This insignificant change of electrical parameters of the Fe-doped diode after proton-irradiation indicates the suppression of the radiation effect by Fe in Si. The electrical properties of the diode are less dependent on incident radiation, because of the possible prevention of further dislodgement of atoms by incident radiation. As a result, the material becomes resistant to radiation damage, making the electrical properties of the diode independent of incident radiation due to Fe atoms in Si. As a result of the ohmic behaviour displayed by the Fe-doped Si diode, it is possible that in Si, Fe is responsible for generation-recombination (g-r) centres, which are defect levels positioned at the middle of the energy gap of Si. The possibility of these defects being responsible for the suppression of the radiation effect is explained in this work, making Fe a promising dopant to improve the radiation-hardness of Si. [ABSTRACT FROM AUTHOR]

The development of advanced neural modulation techniques is crucial to neuroscience research and neuroengineering applications. Recently, optical-based, nongenetic modulation approaches have been actively investigated to remotely interrogate the nervous system with high precision. Here, we show that a thin-film, silicon (Si)-based diode device is capable to bidirectionally regulate in vitro and in vivo neural activities upon adjusted illumination. When exposed to high-power and short-pulsed light, the Si diode generates photothermal effects, evoking neuron depolarization and enhancing intracellular calcium dynamics. Conversely, low-power and long-pulsed light on the Si diode hyperpolarizes neurons and reduces calcium activities. Furthermore, the Si diode film mounted on the brain of living mice can activate or suppress cortical activities under varied irradiation conditions. The presented material and device strategies reveal an innovated optoelectronic interface for precise neural modulations. [ABSTRACT FROM AUTHOR]

Interband cascade light-emitting diodes (ICLEDs) offer attractive advantages for infrared applications, which would greatly expand if high-quality growth on silicon substrates could be achieved. This work describes the formation of threading dislocations in ICLEDs grown monolithically on GaSb-on-Silicon wafers. The epitaxial growth is done in two stages: the GaSb-on-Silicon buffer is grown first, followed by the ICLED growth. The buffer growth involves the nucleation of a 10-nm-thick AlSb buffer layer on the silicon surface, followed by the GaSb growth. The AlSb nucleation layer promotes the formation of 90° and 60° interfacial misfit dislocations, resulting in a highly planar morphology for subsequent GaSb growth that is almost 100% relaxed. The resulting GaSb buffer for growth of the ICLED has a threading dislocation density of ∼107/cm2 after ∼3 μm of growth. The fabricated LEDs showed variations in device performance, with some devices demonstrating comparable light–current–voltage curves to those for devices grown on GaSb substrates, while other devices showed somewhat reduced relative performance. Cross-sectional transmission electron microscopy observations of the inferior diodes indicated that the multiplication of threading dislocations in the active region had most likely caused the increased leakage current and lower output power. Enhanced defect filter layers on the GaSb/Si substrates should provide more consistent diode performance and a viable future growth approach for antimonide-based ICLEDs and other infrared devices. [ABSTRACT FROM AUTHOR]

In‐memory computing significantly reduces workload and energy cost of data access in the traditional von Neumann computing architecture. Using various memristors, stateful logic is developed to realize in‐memory computing. However, memristors have encountered critical issues in terms of device variation and reliability, and therefore, fundamental device solutions are required to realize practical stateful logic. In this study, NAND, NOR, and half‐adder stateful logic operations of gated silicon diodes with a p+–n–p–n+ structure are demonstrated to achieve in‐memory computing. Gated diodes have bistable, steep switching, and quasi‐nonvolatile memory characteristics, enabling reliable stateful logic operation. The uniformity of their device characteristics overcomes the inherent stochastic characteristics of memristors that are widely researched for stateful logic. The sequential multiread logic operation simplifies the complex state logic scheme. In particular, a nondestructive half‐adder operation can be executed in five sequential steps using six parallel diodes. Thus, the stateful logic of gated diodes can be a potential building block for in‐memory computing. [ABSTRACT FROM AUTHOR]

Silicon photonics is a promising technology for the fabrication of dense photonic chips, thanks to the very mature silicon industry. The direct epitaxial growth of III–V lasers on silicon is one of the main challenges for the realization of compact and robust mid-infrared sensors based on photonic integrated circuits. The crystal defects arising from this heteroepitaxial growth affect the laser performance and, therefore, need to be mitigated but also studied to better understand their impact on the laser operation. Here, we studied the effect of threading dislocations on laser performance by comparing the series of GaSb-based diode lasers grown on native GaSb and Si substrates with different numbers of quantum wells (nQW) in their active zones. As expected, the laser threshold currents are higher in the case of diode lasers on Si, and they rapidly vary with nQW. Still, the lowest threshold current densities are achieved with nQW = 1 for both substrates. With the help of a theoretical gain model, we attribute these results to the fact that dislocations create non-radiative recombination but do not introduce additional optical losses. This work allows a better understanding of the origin of performance degradation and the decision to be made regarding the heterostructure design. [ABSTRACT FROM AUTHOR]

Optoelectronic neural interfaces can leverage the photovoltaic effect to convert light into electrical current, inducing charge redistribution and enabling nerve stimulation. This method offers a non-genetic and remote approach for neuromodulation. Developing biodegradable and efficient optoelectronic neural interfaces is important for achieving transdermal stimulation while minimizing infection risks associated with device retrieval, thereby maximizing therapeutic outcomes. We propose a biodegradable, flexible, and miniaturized silicon-based neural interface capable of transdermal optoelectronic stimulation for neural modulation and nerve regeneration. Enhancing the device interface with thin-film molybdenum significantly improves the efficacy of neural stimulation. Our study demonstrates successful activation of the sciatic nerve in rodents and the facial nerve in rabbits. Moreover, transdermal optoelectronic stimulation accelerates the functional recovery of injured facial nerves. Optoelectronic neural interfaces allow for non-genetic and remote modulation of neural activity. Here, the authors propose a biodegradable, flexible and miniaturized neural interface based on molybdenum-modified silicon diodes that allows transdermal neuromodulation and promotes nerve regeneration. [ABSTRACT FROM AUTHOR]

Silicon photonic integrated circuit foundries enable wafer-level fabrication of entire electro-optic systems-on-a-chip for applications ranging from datacommunication to lidar to chemical sensing. However, silicon's indirect bandgap has so far prevented its use as an on-chip optical source for these systems. Here, we describe a fullyintegrated broadband silicon waveguide light source fabricated in a state-of-the-art 300-mm foundry. A reverse-biased p-i-n diode in a silicon waveguide emits broadband near-infrared optical radiation directly into the waveguide mode, resulting in nanowatts of guided optical power from a few milliamps of electrical current. We develop a one-dimensional Planck radiation model for intraband emission from hot carriers to theoretically describe the emission. The brightness of this radiation is demonstrated by using it for broadband characterization of photonic components including Mach-Zehnder interferometers and lattice filters, and for waveguide infrared absorption spectroscopy of liquid-phase analytes. This broadband silicon-based source can be directly integrated with waveguides and photodetectors with no change to existing foundry processes and is expected to find immediate application in optical systems-on-a-chip for metrology, spectroscopy, and sensing. On-chip optical sensing and metrology systems are rapidly progressing, but CMOS-compatible silicon light sources remain a challenge. This work demonstrates a broadband, foundry integrated silicon waveguide emitter and the theory that describes it. [ABSTRACT FROM AUTHOR]

3D trench silicon pixel sensors, recently developed by the TimeSPOT collaboration, have shown excellent performance in terms of spatial resolution, timing precision and detection efficiency. The combination of these three features make them one of the best candidate for inner tracking detectors operating in high luminosity hadron colliders experiments. This article presents systematic characterisations of these devices made with minimum ionising particles on irradiated sensors with neutrons up to 2.5 · 1016 1 MeV neq cm-2. The results show that 3D trench pixels have extremely high resistance to radiation. The measured time resolution and the detection efficiency of irradiated sensors match those of non-irradiated ones if a slightly higher bias voltage, few tens of Volts, is applied to the pixels. As of today, 3D trench pixels are the only sensors capable of achieving 10 ps time resolution after being irradiated at extremely high fluences, extending by far the capabilities of future tracking systems of HEP experiments operating under extreme conditions. [ABSTRACT FROM AUTHOR]

Au-Sn solder has been currently used for soldering the laser diode silicon chip on the slider surface which is alumina (Al2O3) titanium carbide (TiC) in hard disk drive (HDD). However, intermetallic compounds (IMCs) form at the interface during the bonding process and result in cracks within these interfacial IMCs. As a consequence, the bonded joint failure occurs for Au-Sn (IMCs) joints with low shear stress. The shear stress is considered a major contributor to the quality and reliability of HDD. At present, the average shear strength of the Au-Sn (IMCs) joint is approximately 2.716 MPa. In this work, 4,572 Au-Sn bonded samples using the laser transmission bonding process were analysed to find suitable bonding factors to improve the shear stress of Au-Sn (IMCs). The analyse phase utilizes heat map correlation to determine 5 key process input variables (KPIVs) including (1) Temperature, (2) Stage Cross-Track (CT), (3) Stage Down-Track (DT), (4) Z-height (5) Laser power. The key process output variable (KPOV) is the shear strength of the IMCs layer between the laser diode silicon chip and the Alumina Titanium Carbide (AlTiC) substrate. Then, a response surface methodology (RSM) is performed to provide the significant factors that generate a reliable mathematical relationship between the process parameters and the desired response. The confirmation experiment performed illustrates that the new process setting of the IMCs shear strength layer is increased from 2.716 MPa to 5.050 MPa which accounts for 85.94% which is a significant improvement. [ABSTRACT FROM AUTHOR]

Graphene–silicon Schottky diodes are intriguing devices that straddle the border between classical models and two-dimensional ones. Many papers have been published in recent years studying their operation based on the classical model developed for metal–silicon Schottky diodes. However, the results obtained for diode parameters vary widely in some cases showing very large deviations with respect to the expected range. This indicates that our understanding of their operation remains incomplete. When modeling these devices, certain aspects strictly connected with the quantum mechanical features of both graphene and the interface with silicon play a crucial role and must be considered. In particular, the dependence of the graphene Fermi level on carrier density, the relation of the latter with the density of surface states in silicon and the coupling between in-plane and out-of-plane dynamics in graphene are key aspects for the interpretation of their behavior. Within the thermionic regime, we estimate the zero-bias Schottky barrier height and the density of silicon surface states in graphene/type-p silicon diodes by adapting a kown model and extracting ideality index values close to unity. The ohmic regime, beyond the flat band potential, is modeled with an empirical law, and the current density appears to be roughly proportional to the electric field at the silicon interface; moreover, the graphene-to-silicon electron tunneling efficiency drops significantly in the transition from the thermionic to ohmic regime. We attribute these facts to (donor) silicon surface states, which tend to be empty in the ohmic regime. [ABSTRACT FROM AUTHOR]

The article presents the study on the comparison of gain coefficient of laser diode on silicon and InP substrate. Fabry–Perot GaInAsP bulk laser diode on InP/Si substrate is successfully obtained to study the optical gain coefficient of laser diode. The influences of temperature, threshold current comparison, and optical gain achievements between bulk InP/Si laser diode substrate and InP laser diode substrate are also analyzed using the same growth structure. A new approach is found by the research group which involves bonding of 1 μm InP semiconductor crystal and a low‐cost silicon crystal prior to epitaxial laser structure growth. With the help of metal–organic vapor‐phase epitaxy technique, GaInAsP double‐heterostructure laser is epitaxially deposited on the well‐bonded InP/Si crystal. Fabry–Perot lasing under pulsed condition is achieved, and the lasing characteristics of InP/Si substrate are compared with that of InP laser device to study the gain coefficient. [ABSTRACT FROM AUTHOR]

Microstructured neutron detectors have the benefit of enhanced neutron detection efficiency as compared to planar devices, achieved by etching 6LiF-filled trenches on the top surface of a silicon PIN diode. This sensor geometry results in a complex electric field distribution and depletion characteristics within the diode under reverse bias. For the first time on record, the effects of a fixed oxide charge on the microstructured device depletion characteristics and mobile carrier transport is investigated. Prototype detectors were fabricated with non-conformal surface doping. Capacitance voltage and current voltage measurements were performed for these prototypes and compared with COMSOL Multiphysics simulations. A spectral response from an 241Am alpha particle source was acquired and analyzed. It was found that monoenergetic alpha particles produce three prominent peaks in the pulse height spectrum output by the device. The peaks were confirmed by simulations to correlate with dead layers and incident trajectories into the microstructure. It was also found that significant differences in pulse rise time result, corresponding with events arriving in a low-field region in the fins and a high-field region in the bulk. Geant4 was utilized for radiation transport, interaction modeling, and benchmarking the spectral data. The results of this simulation work provide confidence in the ability to attain and benchmark electrical characteristics and spectral data for semiconductor radiation detectors employing complex microstructures. [ABSTRACT FROM AUTHOR]

This Letter reports the performance of vertical GaN-on-GaN p–n diodes with etch-then-regrown p-GaN after exposure to a simulated Venus environment (460 °C, ∼94 bar, containing CO2/N2/SO2 etc., atmosphere) for over 10 days, and compared them to the performance of GaN p–n diodes without the etch-then-regrow process. After the above-mentioned Venus test, temperature-dependent I–V and microscopy investigation were conducted to study the robustness of etch-then-regrow p-GaN and vertical GaN p–n diodes under harsh environments and operation up to 500 °C. p-electrode degradation is found to be the main issue of the device's performance. This is the highest temperature at which such characterization has been conducted for vertical GaN p–n diodes, therefore establishing a critical reference for the development of p-GaN regrown and vertical GaN-based electronics for extreme environments. [ABSTRACT FROM AUTHOR]

Mach–Zehnder interferometers (MZIs) integrated with phase‐change materials have attracted great interest due to their low power consumption and ultra‐compact size, which are favored for reconfigurable photonic processors. However, they suffer from a low optical extinction ratio and limited switching cycles due to high material loss and poor reversible repeatability caused by material degradation. Here a non‐volatile electrically reconfigurable 2 × 2 MZI integrated with a low‐loss phase‐change material Sb2Se3 encapsulated in Al2O3 layers is demonstrated. The phase change is electrically actuated by a forward‐biased silicon p‐i‐n diode. The switch extinction ratio is more than 20 dB due to the low‐loss Sb2Se3‐based phase shifter. By dividing the Sb2Se3 patch into small sub‐cells to restrict the material reflow, more than 10 000 reversible phase‐change cycles and 6‐bit multilevel switching states are achieved by programming the electrical pulses. Its non‐volatility, high endurance, and fine‐tuning capability makes the device promising in large‐scale low‐power reconfigurable photonic processors. [ABSTRACT FROM AUTHOR]

The topology of grid-connected seven-switch boost-type current source inverter (CSI7) is a promising alternative to the conventional six-switch current source inverter (CSI) due its superiority in terms of reliability and energy efficiency. It is a simple single-stage boost-type converter that allows the injection of high quality sinusoidal AC-currents with controllable power factor into the grid with a DC-link voltage lower than the grid voltage amplitude. This paper evaluates the performance of grid-connected photovoltaic (PV) CSI7 in terms of power losses and efficiency considering distinct configurations of the voltage reverse blocking power switches, i.e., silicon IGBTs (Si-IGBTs) in series with hyper-fast recovery silicon diodes (Si-HFRDs) and Si-IGBTs in series with wide band-gap silicon-carbide Schottky-barrier diodes (SiC-SBDs). The proposed investigation is based on experimental tests and combined electrical-thermal computer co-simulations using PLECS and simulink. The obtained results empathize the features of SiC-SBDs based power switches in terms of reducing the inverter's power losses and improving the overall system efficiency. They also demonstrate the high performance of the CSI7 topology in terms of power quality in grid-connected PV applications. [ABSTRACT FROM AUTHOR]

Silicon membrane strip photodetectors are fabricated based on thin silicon-on-insulator (SOI) wafers. The thin SOI wafer is realized by exploiting a thinning process on backside. Such detectors can be implemented in proton-beam position detection because its ultra-thin membrane substrate can reduce beam scattering and offer the considerable advantages of higher radiation hardness. A p-spray implantation process is typically performed at the silicon surface between the n + -strips in order to insulate them, without requiring an extra photolithographic mask. In this paper, the sources of leakage current in the detector are first studied by considering both activation energy and simulation analysis in Silvaco TCAD. While the device is operating below avalanche breakdown voltage, the Shockley–Read–Hall process and trap-assisted-tunneling process are dominantly contributing to leakage current. The dominant breakdown voltage is attributed to the premature breakdown in the junction of p − spray / n + region. The shift of this breakdown voltage under repeated avalanche processes is analyzed in-depth by both experiments and simulations, as a function of temperature and electrical stress conditions, which are introducing an important reliability problem. The electrical stress can be attributed to an increase in fixed charge density at the Si/ SiO 2 interface. The breakdown voltage finally increases by 4 V after successive avalanche breakdowns as a function of the applied excess bias voltage beyond breakdown voltage. [ABSTRACT FROM AUTHOR]

The effects of gamma and proton irradiation, and of forward bias minority carrier injection, on photo-response were investigated for InAsSb/AlAsSb pBn mid-wave infrared (MWIR) detectors with an engineered majority-carrier barrier. Room-temperature gamma irradiation had an insignificant effect on 77 K photo-response. Gamma irradiation at 77 K detector temperature, however, decreased in situ photo-response by 19% after a cumulative dose of ~ 500 krad(Si). Subsequent forward bias minority carrier injection had no effect on photo-response. The 77 K detectors irradiated with 30 MeV protons up to 2 Mrad(Si) had photo-response degraded by up to 70%, but here forward bias minority carrier (hole) injection caused up to 12% recovery that persisted more than 30 min. These results suggest a mitigation strategy for maintaining the photo-response of similar detectors in radiation environments that cause displacement damage defects. [ABSTRACT FROM AUTHOR]

The performance of organic photodetectors is steadily improving, and the specific detectivity, as a key figure of merit, has reached values of 1012–1013 Jones, i.e., comparable to that of silicon diodes but still considerably lower than the intrinsic limit. As with other semiconductor devices, the electrical performance of state‐of‐the art organic photodiodes (OPDs) is presently determined to a high degree by the presence of chemical impurities or structural defects which create carrier trapping states within the bandgap of organic active layer. This review aims to provide a comprehensive and timely account of trap‐assisted charge generation and recombination in OPDs, with emphasis on the impact of these phenomena on photodetector performance parameters such as, noise and dark current density, responsivity, response speed, and ultimately, specific detectivity. [ABSTRACT FROM AUTHOR]

Capacitive analogues of semiconductor diodes (CAPodes) present a new avenue for energy‐efficient and nature‐inspired next‐generation computing devices. Here, we disclose the generalized concept for bias‐direction‐adjustable n‐ and p‐CAPodes based on selective ion sieving. Controllable‐unidirectional ion flux is realized by blocking electrolyte ions from entering sub‐nanometer pores. The resulting CAPodes exhibit charge‐storage characteristics with a high rectification ratio (96.29 %). The enhancement of capacitance is attributed to the high surface area and porosity of an omnisorbing carbon as counter electrode. Furthermore, we demonstrate the use of an integrated device in a logic gate circuit architecture to implement logic operations ('OR', 'AND'). This work demonstrates CAPodes as a generalized concept to achieve p‐n and n‐p analogue junctions based on selective ion electrosorption, provides a comprehensive understanding and highlights applications of ion‐based diodes in ionologic architectures. [ABSTRACT FROM AUTHOR]

In this work, we design and simulate a three-dimensional (3D) SU-8 tapered edge coupler for effectively guiding light from an edge-emitting semiconductor laser diode directly to a silicon waveguide to realize a hybrid on-chip silicon light source. A series of coupling efficiencies for the commonly used top silicon thicknesses of the silicon-on-insulator wafers from 220 to 3000 nm are obtained, showing that this polymer taper can largely improve the coupling efficiency when the silicon waveguide thickness is moderate, for instance, from 41% (with no taper) to 67% for the 700 nm- thick silicon waveguide under 1 μ m gap offset and relax the lateral misalignment tolerance to above one micron by suppressing the butt refractive index contrast and the mode mismatch between the laser diode and the silicon waveguide. Wave transformation inside the tapered coupler and the input silicon waveguide has also been revealed by 3D finite-difference time-domain simulations. This 3D tapered coupler is cost effective and easily fabricated which can have wide practical applications in massive production of various silicon photonic chips based on the present complementary metal-oxide-semiconductor foundry. [ABSTRACT FROM AUTHOR]

A fused silica dilatometer consisted of a rod and tube that had capacitance discs attached at one end. The cylindrical specimen of polycrystalline pure silicon 2.54 cm long and 0.635 cm in diameter was clamped between the other end of the rod and tube. These were enclosed in a fused silica furnace tube within the furnace. The furnace tube was sealed with helium that did not flow. The capacitance discs were sealed in a container outside of the furnace. Helium flowed within that container. These disks were used to measure the thermal expansion of pure silicon between 20 °C and 600 °C. The capacitance measurements were made by an Andean Hagerling capacitance bridge with a readout of ten digits and a sensitivity of 0.5 attofarads. The rate of heating and cooling was 1 °C·min−1. The specimen temperature was measured using a calibrated platinum thermometer 3 mm away from the specimen. To correct for changes in disc expansion during a test, a silicon diode measured the temperature. Calibration of the capacitor extensometer was made using NIST fused silica and NIST stainless steel. The total thermal expansion of three silicon specimens measured between 20 °C and 600 °C was 2074.83 µstrain with a standard deviation of 17.43 µstrain. The hysteresis difference between the warming and cooling curves for the silicon was less than 7 µstrain. [ABSTRACT FROM AUTHOR]

We realize single-mode, waveguide-coupled, electrically driven silicon light emitting diodes in commercial, unmodified silicon photonics foundry processes and develop a model of both the electrical and optical behavior to understand the performance limitations. We measure a center wavelength of 1130 nm, a 90 nm 3 dB optical bandwidth, and 200 pW of optical power propagating in each direction. We show on-chip modulation and detection of the generated light using native resonant photodetectors integrated in the same chip. Our work unveils a new native light source available in silicon photonics processes, which can find applications ranging from device screening and fabrication quality assessment to imaging, refractive index sensing, or intra-chip communication. [ABSTRACT FROM AUTHOR]

Quasi-vertical gallium nitride (GaN) Schottky diodes on silicon carbide (SiC) substrates were fabricated for frequency multiplier applications. The epitaxial structure employed had an n− layer of 590 nm with doping 6.6 × 1016 cm−3, while the n+ layer was 950 nm thick, with doping 2 × 1019 cm−3. Potassium hydroxide (KOH) chemical surface treatment before Schottky contact metallization was employed to study its effect in improving the diode parameters. The KOH-treated diode demonstrated a breakdown voltage of − 27.5 V, which is the highest reported for this type of diode. Cut-off frequencies around 500 GHz were obtained at high reverse bias (− 25 V) in spite of high series resistance. The result obtained in breakdown voltage value warrants further research in surface treatment and post-annealing of the Schottky contact optimization in order to decrease the series resistance. [ABSTRACT FROM AUTHOR]

Silicon light-emitting diodes with dislocation-related electroluminescence have been studied at room temperature. For the fabrication of the light-emitting diode structures, a well-known method for the formation of dislocation- related luminescence centers during anneals of silicon with a high oxygen concentration in a flow of argon was modified by introducing a preliminary O+ ion implantation and carrying out a final anneal in a chlorine-containing atmosphere. In the electroluminescence spectra, the D1 dislocation-related luminescence line dominates at currents less than <150 mA and the near-band-edge luminescence line starts to dominate with increasing current. The electroluminescence excitation efficiency for the D1 center is 3.3 × 10–20 cm2 s at room temperature. [ABSTRACT FROM AUTHOR]

Scalable programmable photonic integrated circuits (PICs) can potentially transform the current state of classical and quantum optical information processing. However, traditional means of programming, including thermo-optic, free carrier dispersion, and Pockels effect result in either large device footprints or high static energy consumptions, significantly limiting their scalability. While chalcogenide-based non-volatile phase-change materials (PCMs) could mitigate these problems thanks to their strong index modulation and zero static power consumption, they often suffer from large absorptive loss, low cyclability, and lack of multilevel operation. Here, we report a wide-bandgap PCM antimony sulfide (Sb2S3)-clad silicon photonic platform simultaneously achieving low loss (<1.0 dB), high extinction ratio (>10 dB), high cyclability (>1600 switching events), and 5-bit operation. These Sb2S3-based devices are programmed via on-chip silicon PIN diode heaters within sub-ms timescale, with a programming energy density of ~ 10 f J / n m 3 . Remarkably, Sb2S3 is programmed into fine intermediate states by applying multiple identical pulses, providing controllable multilevel operations. Through dynamic pulse control, we achieve 5-bit (32 levels) operations, rendering 0.50 ± 0.16 dB per step. Using this multilevel behavior, we further trim random phase error in a balanced Mach-Zehnder interferometer. Phase change materials (PCMs) are promising for low-power programmable photonic circuits. Here, authors show electrically controlled wide-bandgap PCM antimony sulfide achieving low loss, high cyclability and up to 32 levels, and post-fabrication trimming is also demonstrated. [ABSTRACT FROM AUTHOR]

Silicon solar cells featuring tunnel oxide passivated contacts (TOPCon) benefit from high efficiencies and low production costs and are on the verge of emerging as the new photovoltaic market mainstream technology. Their association with Perovskite cells in 2-terminal tandem devices enables efficiency breakthroughs while maintaining low fabrication costs. However, it requires the design of a highly specific interface to ensure both optical and electrical continuities between subcells. Here, we evaluated the potential of tunnel diodes as an alternative to ITO thin films, the reference for such applications. The PECV deposition of an nc-Si (n+) layer on top of a boron-doped poly-Si/SiOx passivated contact forms a diode with high doping levels (>2 × 1020 carrier·cm−3) and a sharp junction (<4 nm), thus reaching both ESAKI-like tunnel diode requirements. SIMS measurements of the nc-Si (n+) (deposited at 230 °C) reveal an H-rich layer. Interestingly, subsequent annealing at 400 °C led to a passivation improvement associated with the hydrogenation of the buried poly-Si/SiOx stack. Dark I–V measurements reveal similar characteristics for resistivity samples with or without the nc-Si (n+) layer, and modeling results confirm that highly conductive junctions are obtained. Finally, we produced 9 cm2 nip perovskite on silicon tandem devices, integrating a tunnel diode as the recombination junction between both subcells. Working devices with 18.8% average efficiency were obtained, with only 1.1%abs PCE losses compared with those of references. Thus, tunnel diodes appear to be an efficient, industrially suitable, and indium-free alternative to ITO thin films. [ABSTRACT FROM AUTHOR]

The semi-conductor SRDN-3a probe, an AlphaE detector with a silicon diode in a diffusion chamber, an AlphaGUARD monitor with an ionization chamber and CR-39 track detectors had been tested simultaneously in long-term measurements conducted in the technical corridor of Dobromierz dam. The passive detectors were exposed twice: for 56 days, and 117 days, others in parallel, with a 1-h data recording interval. The data distribution was tested with the Shapiro–Wilk test and outliers in the critical region were identified using Shewhart control charts. The correctness was evaluated by a z-score test recommended by the IAEA. The characteristics of outliers for each detectors are determined by the location of the critical region (a two-sided region and a positive skew). These are 13.0% and 13.5% for AlphaE, and 9.81% for SRDN-3a. For the reference device, these are 15.8% and 10.5%. The z-score test confirm that all the detectors can be successfully used both in commercial and scientific monitoring measurements. [ABSTRACT FROM AUTHOR]

In order to satisfy the special demand of AR products for ultra‐high luminescence and high resolution full‐color silicon‐based OLED micro displays, a silicon‐based OLED micro display with resolution of more than 4000 ppi (0.36 inch with 1280×720) and a luminescence of more than 5000 nit is investigated. First, the design scheme of high‐resolution silicon‐based OLED driver is introduced. Based on the scheme of strong microcavity effect OLED device, the structure of red, green and blue monochrome luminescence enhancement is verified, and the current efficiency reaches 60 cd A‐1, 95 cd A‐1 and 6 cd A‐1, respectively. Finally, the development of HD036 chip is finished, and the high luminescence full‐color silicon‐based OLED micro display device with ppi more than 4000, luminescence more than 5000 nit, and color gamut more than 85% is achieved. The effect of virtual reality overlay display is achieved by the verification of AR machine. [ABSTRACT FROM AUTHOR]

Small-pitch 3D pixel sensors have been developed to equip the innermost layers of the ATLAS and CMS tracker upgrades at the High Luminosity LHC. They feature 50 × 50 and 25 × 100 μ m 2 geometries and are fabricated on p-type Si–Si Direct Wafer Bonded substrates of 150 μ m active thickness with a single-sided process. Due to the short inter-electrode distance, charge trapping effects are strongly mitigated, making these sensors extremely radiation hard. Results from beam test measurements of 3D pixel modules irradiated at large fluences ( 10 16 n e q / cm 2 ) indeed demonstrated high efficiency at maximum bias voltages of the order of 150 V. However, the downscaled sensor structure also lends itself to high electric fields as the bias voltage is increased, meaning that premature electrical breakdown due to impact ionization is a concern. In this study, TCAD simulations incorporating advanced surface and bulk damage models are used to investigate the leakage current and breakdown behavior of these sensors. Simulations are compared with measured characteristics of 3D diodes irradiated with neutrons at fluences up to 1.5 × 10 16 n e q / cm 2 . The dependence of the breakdown voltage on geometrical parameters (e.g., the n + column radius and the gap between the n + column tip and the highly doped p + + handle wafer) is also discussed for optimization purposes. [ABSTRACT FROM AUTHOR]

The decommissioning of nuclear installations, as well as the possible necessary accident remediations, requires the physical presence of human operators in potentially radiologically hostile environments. The number of active nuclear reactors worldwide is greater than 400, and most of them are 40 to 50 years old, thus implying that soon they will have to be dismantled. In the framework of the H2020 CLEANDEM project, a small robotic vehicle is being developed that is equipped with a series of different sensors for areas that are significantly contaminated by radiation. In this work, we describe the MiniRadMeter system, a compact low-cost sensor capable of being used to perform quick gamma and neutron radiation field mapping of environments prior to the possible start of human operations. The miniature gamma sensor is a 1 cm3 scintillator counter with moderate spectroscopic features read out by means of a 6 × 6 mm2 SiPM, whereas neutrons are detected by means of a silicon diode coupled to a layer of 6LiF and placed inside a 6 × 6 × 6 cm3 polyethylene box. The front-end and data acquisition electronics were developed based on a Raspberry Pi4 microcomputer. In this paper, the system performance and the preliminary test results are described. [ABSTRACT FROM AUTHOR]

Highlights: Large-area production of self-standing graphene nanofilm (~ 20 cm) through a clean 'substrate replacement' strategy. Realizing highly crystalline graphene nanofilms without micro-gasbags by introducing polymers. The graphene nanofilms demonstrate a solid light–matter interaction (photoelectric conversion in the mid-infrared and electromagnetic interference (EMI) shielding in X-band) with performance beyond state-of-the-art graphene/silicon diodes and EMI materials. Bulk graphene nanofilms feature fast electronic and phonon transport in combination with strong light–matter interaction and thus have great potential for versatile applications, spanning from photonic, electronic, and optoelectronic devices to charge-stripping and electromagnetic shielding, etc. However, large-area flexible close-stacked graphene nanofilms with a wide thickness range have yet to be reported. Here, we report a polyacrylonitrile-assisted 'substrate replacement' strategy to fabricate large-area free-standing graphene oxide/polyacrylonitrile nanofilms (lateral size ~ 20 cm). Linear polyacrylonitrile chains-derived nanochannels promote the escape of gases and enable macro-assembled graphene nanofilms (nMAGs) of 50–600 nm thickness following heat treatment at 3,000 °C. The uniform nMAGs exhibit 802–1,540 cm2 V−1 s−1 carrier mobility, 4.3–4.7 ps carrier lifetime, and > 1,581 W m−1 K−1 thermal conductivity (nMAG-assembled 10 µm-thick films, mMAGs). nMAGs are highly flexible and show no structure damage even after 1.0 × 105 cycles of folding–unfolding. Furthermore, nMAGs broaden the detection region of graphene/silicon heterojunction from near-infrared to mid-infrared and demonstrate higher absolute electromagnetic interference (EMI) shielding effectiveness than state-of-the-art EMI materials of the same thickness. These results are expected to lead to the broad applications of such bulk nanofilms, especially as micro/nanoelectronic and optoelectronic platforms. [ABSTRACT FROM AUTHOR]

electroluminescence has been studied in silicon light-emitting diodes containing oxygen precipitates at temperatures of 40–300 K. Oxygen ion implantation and multistage anneals are used for fabrication of the diodes. Over all temperature range, spectra are well approximated by one Lorentz and four Gaussian curves. Lines of dislocation-related luminescence D1–D4 (the D1 line is described by Lorentz curve) and oxygen precipitates (OPs) are present in the spectra. At temperature variation, peak positions of the D1, OP, and D2 lines coincide with temperature dependence of the forbidden gap width reduced by values of 356, 330, and 303 meV respectively. Build and quenching areas are observed on temperature dependences of the electroluminescence intensities of the D1, OP, and D2 lines, the activation energies of the processes are determined, and reasons of their appearance are discussed. [ABSTRACT FROM AUTHOR]

Several methods to detect thermal neutrons make use of the naturally occurring 6Li isotope, as it has a rather high cross-section for neutron capture followed by a decay into an alpha particle and a triton. Due to the high chemical reactivity of lithium, the use of the stable isotopic salt 6LiF is generally preferred to the pure 6Li. The typical method for depositing thin layers of 6LiF on suitable substrates, therefore creating so-called neutron converters, is evaporation under vacuum. The evaporation technique, as well as a newly developed chemical deposition process, are described along with their benefits and drawbacks, and the results of neutron detection tests performed with the two types of converters coupled to silicon diodes show convenient performances. [ABSTRACT FROM AUTHOR]

Experimental samples of silicon diode temperature sensors for cryogenic thermometry are prepared. The process spread and variability of these diode temperature sensors and their effect on the parameters of these diode temperature sensors are studied. In particular, it was found that the spread of the base region doping level in the samples did not exceed 20%, the thickness spread of the base region is 3.5%. The measurement accuracy is highly dependent on the ideality factor spread: at room temperature and when the operating current is 1 μA, 1% change in the value of the ideality factor leads to a measurement error of ± 0.35 °C and a change of 10% leads to a measurement error of ± 3.6 °C. [ABSTRACT FROM AUTHOR]

We have designed a prototype of silicon carbide PIN diode for tritium detection. Monte-Carlo calculations showed the necessity to work in vacuum and employ thin and low-density coating layers, and drew the energy deposition profile in the device. The deposited energies have then been used to implement finite-elements simulations, in order to optimize three structural parameters (n − doping concentration, p doping concentration, p zone thickness) maximizing the electrical response. Temperature lowering improves the diode electrical response. • Numerical conception of SiC-based diode for tritium detection. • Monte-Carlo optimization of ambient air pressure, and coatings materials. • Finite-elements optimization of n- and p+ doping concentration, and p+ zone thickness. [ABSTRACT FROM AUTHOR]

This study describes the synthesis of barium (Ba) and strontium (Sr) thin films using jet neublizer spray pyrolysis (JNSP) technology, which facilitates the fabrication of junction diodes whose structure, surface morphology, and optical properties are affected by significant water absorption. Ba–Sr films with different strontium concentrations (specifically 0, 2, 4 and 6 wt%) were further investigated to provide a better understanding of how this change affects the final diode type. The research design focuses on fabricating n-type silicon junction diodes containing barium and strontium and directly measuring and analyzing their I–V characteristics, ultimately helping elucidate these devices' electrical behavior. Among the analyzed diodes, the Ag/Ba–Sr/n-Si/Ag diode performed well in various design tests, indicating its competitiveness due to its goodness in optoelectronic devices. The ideal value (n) of a 6 wt% Ba–Sr diode is 1.77 and the barrier height (Φ B) is 0.84 eV. These results demonstrate the general future of Ba–Sr junction diode, as they not only reveal important discoveries regarding their electrical properties but also demonstrate the potential for improved performance in optoelectronic applications. [Display omitted] • A sensitive Ag/Ba–Sr/n-Si/Ag structured junction diode was efficaciously fabricated by JNSP process. • Strangely, UV–Vis analysis revealed a smaller band gap of 3.18 eV in samples heated at higher substrate temperatures. • Especially, 6 wt% Ba–Sr produced the best diode with n = 1.77 and ϕ B = 0.84 eV. • To enhance diode performance, a high dielectric material can be introduced in the fabrication of a p-n junction diode. [ABSTRACT FROM AUTHOR]

The impact of radiation on Si-based detectors garnered interest due to the observed degradation in their stability in high-radiation environments. In this study, we examined the effects of 3 MeV proton irradiation on both undoped and Al-doped n -Si diodes using I–V technique. The results revealed a decline in current trends for both types of diodes post-irradiation. This decrease was attributed to defects created by proton irradiation, which acted as recombination or trapping centres. However, the Al-doped n -Si diodes experienced a lesser decline in measured current, hinting at the radiation suppression effect of Al doping in Si. Additionally, Al-doped n -Si diodes displayed minimal changes in their diode parameters after irradiation, and their conduction mechanism remained unchanged. These results suggested that Al-doped n -Si diodes had superior stability compared to their undoped counterparts, implying that the presence of Al enhanced the diodes' resistance to radiation. The radiation suppression effect of Al seemed to stem from its ability to produce defects that improve Si's radiation-hardness, thereby mitigating the introduction of additional instability-causing defects during proton irradiation. Thus, incorporating Al was recommended for research aiming to improve the radiation resistance of Si. • Study explores 3 MeV proton impact on undoped and Al-doped n -Si diodes using I–V techniques. • Al-doped n -Si diodes show radiation suppression, with less current decline and minimal parameter changes after irradiation. • Al-doped n -Si diodes enhance Si-based detector radiation resistance by introducing stable defects through Al doping. [ABSTRACT FROM AUTHOR]

The rapid growth of wireless technology has improved the network's technology from 4G to 5G, with sub-6 GHz being the centre of attention as the primary communication spectrum band. To effectively benefit this exclusive network, the improvement in the mm-wave detection of this range is crucial. In this work, a silicon self-switching device (SSD) based full-wave bridge rectifier was proposed as a candidate for a usable RF-DC converter in this frequency range. SSD has a similar operation to a conventional pn junction diode, but with advantages in fabrication simplicity where it does not require doping and junctions. The optimized structure of the SSD was cascaded and arranged to create a functional full-wave bridge rectifier with a quadratic relationship between the input voltage and outputs current. AC transient analysis and theoretical calculation performed on the full-wave rectifier shows an estimated cut-off frequency at ~12 GHz, with calculated responsivity and noise equivalent power of 1956.72 V/W and 2.3753 pW/Hz1/2, respectively. These results show the capability of silicon SSD to function as a full-wave bridge rectifier and is a potential candidate for RF-DC conversion in the targeted 5G frequency band and can be exploited for future energy harvesting application. [ABSTRACT FROM AUTHOR]

Integrated field-emission devices and integrated circuits (ICs) based on them are a promising direction in microelectronics, which is associated with the use of low-voltage and stable field emitters based on nanomaterials, such as carbon nanotubes (CNTs). The planar design of the field-emission device makes it possible to form CNTs at the end of a thin catalyst film 1–50 nm thick. The paper presents the results of the implementation of an integrated technology for manufacturing planar field-emission diodes with a CNT cathode formed at the end of a thin conducting film. The CNTs are grown by chemical-vapor deposition. A thin film of initially amorphous Co–Nb–N–(O) alloy is used as the growth catalyst. A feature of the technology is the crystallization of Co–Nb–N–(O) alloy during heating in the process of chemical-vapor deposition. As a result, Co nanoparticles are formed on the alloy surface, which catalyze the growth of CNTs. It is shown that this specific feature makes it possible to form CNTs locally, only in open areas of the Co–Nb–N–(O) alloy, for example, at the ends of a thin film. The choice of the Co–Nb–N–(O) alloy is substantiated. The stages of formation of planar field-emission diodes on a silicon substrate are described using standard manufacturing processes. The results of measuring the I–V characteristics of devices are presented. It is shown that the type of I–V characteristics is determined by the field emission characteristic of CNTs. The developed technological method for the local synthesis of CNTs at the ends of topologically formed regions of a thin Co–Nb–N–(O) alloy film can be incorporated into an integrated technology for the formation of planar field-emission devices. [ABSTRACT FROM AUTHOR]