Semiconductor Resistance Research Articles

Radiation Hardness and Defects Activity in PEA2PbBr4 Single Crystals

AbstractMetal halide perovskites (MHPs) are low‐temperature processable hybrid semiconductor materials with exceptional performances that are revolutionizing the field of optoelectronic devices. Despite their great potential, commercial deployment is hindered by MHPs lack of stability and durability, mainly attributed to ion migration and chemical interactions with the electrodes. To address these issues, 2D layered MHPs are investigated as possible device interlayers or active material substitutes. Here, the 2D perovskite (PEA)2PbBr4 is considered that is recently discussed as promising candidate for X‐ray direct detection. While the increased resilience of (PEA)2PbBr4 radiation detectors has already been reported, the physical mechanisms responsible for such improvement compared to 3D perovskites are not still fully understood. To unravel the charge transport process in (PEA)2PbBr4 crystals thought to underly the device better performance, an investigation technique is adapted previously used on highly resistive inorganic semiconductors, called photo induced current transient spectroscopy (PICTS). It is demonstrated that PICTS can reliably detect three trap states (T1, T2, and T3), and that their evolution upon X‐ray exposure can explain (PEA)2PbBr4 superior radiation tolerance and reduced aging effects. Overall, the results provide essential insights into the electrical characteristics of 2D perovskites and their potential application as reliable direct X‐ray detectors.

Characterization and Control of Carbon Nanotube Doping

Carbon nanotube FETs show great promise for beyond-Si and monolithic 3D electronics, however there are still fundamental questions to explore. In particular, controlled N- and P- doping is a fundamental process module which can be used to engineer semiconductor resistance in un-gated regions such as the contact or extension, as well as optimize band-to-band tunneling leakage [1-4]. To-date both N- and P- doping has been demonstrated for CNT, but the optimal strategies for doping control and carrier density quantification have not been determined. In this work, we present a study of N- and P- doping using solid-state dopants and doping control strategy using a dielectric barrier of tunable thickness. A TCAD evaluation reveals the tradeoffs between carrier density and mobility for increasing dielectric barrier thickness, and reveals the critical role of dielectric constant in optimizing performance of spacer doping [5]. Multiple characterization approaches under evaluation help to correlate doping strength to experimentally measurable quantities with insight into the doping mechanisms. Finally, we will summarize potential approaches for improving doping control and quantification, and progress towards integration of the doping in highly-scaled high-performance carbon nanotube FETs [6].[1] Z. Zhang, et al., “Complementary carbon nanotube metal-oxide-semiconductor field-effect transistors with localized solid-state extension doping,” Nature Electronics, 2023.[2] Q. Lin, et al., “Band-to-band Tunneling Leakage Current Characterization and Projection in Carbon Nanotube Transistors,” ACS Nano, 2023.[3] G. Zeevi, et al., “PN Junction and band to band tunneling in carbon nanotube transistors at room temperature,” Nanotechnology, 2021.[4] L. Liyanage, et al., “VLSI-compatible carbon nanotube doping technique with low work-function metal oxides,” Nano Letters, 2014.[5] C. Gilardi et al., “Barrier Booster for Remote Extension Doping and its DTCO for 1D & 2D FETs”, IEDM 2023[6] S.Li, et al., “High-performance and low parasitic capacitance CNT MOSFET: 1.2 mA/μm at VDS of 0.75 V by self-aligned doping in sub-20 nm spacer,” IEDM 2023.

Light Dependent Negative Differential Resistance and Resistive Switching in Oxide Semiconductors

Light Dependent Negative Differential Resistance and Resistive Switching in Oxide Semiconductors

Ultra-low-power super class-AB adaptive biasing operational transconductance amplifier with enhanced gain for biomedical applications

The operational transconductance amplifier (OTA) proposed in this article is a bulk-driven (BD), single-stage, super-class-AB, adaptive biasing, functioning in the subthreshold region (ST) with an enormously low power supply of ± 0.25 V, providing high-gain. The input core of the OTA circuit is composed of adaptively biased BD differential input pairs based on flipped voltage follower (FVF), which drive in class-AB mode with a partial positive feedback (PPF) approach. The circuit additionally employs FVF and self-cascode (SC)-based low-power current mirror loads at its output to obtain significantly high gain and unity gain frequency. In addition, using adaptive loads based on source-degenerated metal oxide semiconductor (MOS) resistors raises dynamic current more efficiently, consequently improving the slew rate and unity gain frequency (UGF) without drawing additional power. Employing the cadence spectre tool and the UMC 0.18 μm complementary metal oxide semiconductor (CMOS) process technology, the designed OTA has been simulated. The simulation outcomes substantiate that the amplifier provides high open loop DC gain of 75 dB, 18.75 kHz UGF with a phase margin of 63.93º, and input-referred noise (IRN) of 0.734 µV/Hz0.5 at 1 kHz frequency. The proposed OTA consumes just 60.15 nW of power. The performance results confirmed that the proposed OTA circuit is appropriate in biomedical applications.

The study on influence factors of contact properties of metal-MoS2 interfaces

The metal and two-dimension (2D) semiconductor contact interfaces have a more considerable contact resistance hindering carrier injection, which makes the performance of 2D semiconductor devices less than the theory. The contact properties of Ni, Au, and Mo with MoS2 are simulated by the first-principles method. The interface dipole caused by the interface charge redistribution changes the work function difference at the metal-MoS2 interface, so the interface charge redistribution is one of the important factors for correctly evaluating the contact properties. Due to the metal-induced gap states (MIGS) at metal-monolayer (ML) MoS2 interfaces, the Fermi level is strongly pinned to fixed energy, and the Schottky barrier height (SBH) cannot be regulated efficiently by the metal work function. Although the work function of Au is bigger than Ni, the Fermi level of Au is pinned at a higher position. In the meantime, the bandgap of MoS2 narrows and metallization occurs due to the larger MIGS. In the Mo-MoS2 interface, the Fermi level is pinned near the conduction band minimum of MoS2. The contact resistances (Rc) of the three structures are tested by the Circular Transfer Length Method (CTLM), which is consistent with the prediction of the simulation. The Mo-MoS2 has the smallest Rc. The results indicate that contact resistance of 2D semiconductors cannot be simply predicted by soled work functions or Fermi level pinning, but is determined by several factors.

P‐225: Late‐News Poster: Improving Specific Contact Resistivity of a‐IGZO Thin‐Film‐Transistors via Multi‐stack Interlayer

We report the effects of sputter‐based multi‐stack interlayer on the electrical contact properties of a‐IGZO TFTs. The a‐IGZO TFTs with a multi‐stack interlayer of TiN and IGTO showed remarkable outcomes, including the lowest specific contact resistivity (ρC) and the highest field‐effect mobility (μFET). This research suggests a highly effective approach to reduce the contact resistivity of oxide semiconductors by nearly two orders magnitude.

스프레이 프린팅된 1 V 이하의 유연한 전해질 게이트 인버터

We demonstrate all-printed, low-voltage, and flexible electrolyte-gated transistors and inverters prepared through a facile spray-printing process. All active components of the electronic circuits, including source/drain electrodes, semiconductor, gate dielectric, gate electrode, and load resistor, were directly deposited via spray printing. The sprayed transistors show a high on/off ratio of ∼104. The printed devices also show excellent operational stability under successive bending stresses, maintaining 88% of their performance after 5,000 bending cycles at a small bending radius of 2 mm. Furthermore, the resistor-loaded flexible inverters exhibit appropriate rail-to-rail voltage inverting characteristics with a high voltage gain of ~9 at a low supply voltage of −1 V. These results demonstrate that the high-throughput strategy is promising for generating low-voltage, flexible, and all-spray-printed electronic circuits.

Fabrication and characterization of diamond (100) p+-i-n+ diodes with heavily nitrogen-doped films

N-type diamond-based diodes are currently faced with challenges associated with high contact resistance at the interface of the metal and n-type semiconductor. To address this issue, we attempt to reduce the contact resistance by utilizing a heavily nitrogen-doped film with a nitrogen impurity concentration of 8.0 × 1020/cm3. In the fabricated p+-i-n+ device, we observed a rectification ratio of six orders of magnitude at ±10 V and a built-in voltage of 3.5 V. These findings mark a significant milestone as they represent the first-ever report of room-temperature operation in a device that utilizes a heavily nitrogen-doped film as the n+-layer. This breakthrough has effectively overcome the high contact resistance in n-type diamond semiconductors. The implications of our findings are substantial, as they expand the potential of nitrogen in diamond power devices.

Properties of photocurrent and metal contacts of highly resistive ultrawide bandgap semiconductors

Properties of photocurrent and metal contacts of highly resistive ultrawide bandgap semiconductors

Alternatives to Fluoropolymers for Motion-Based Energy Harvesting: Perspectives on Piezoelectricity, Triboelectricity, Ferroelectrets, and Flexoelectricity.

Fluoropolymers, including polytetrafluoroethylene (PTFE, Teflon), polyvinylidene difluoride (PVDF), and fluorine kautschuk materials (FKMs, Viton) are critical polymers for applications ranging from non-stick coatings, corrosion resistant seals, semiconductor manufacturing, membranes, and energy harvesting technologies. However, the synthesis of these fluoropolymers requires the use of per- and polyfluorinated alkyl substances (PFAS) known colloquially as "forever chemicals," and as such there is a pressing need to develop alternative technologies that can serve the end-use of fluoropolymers without the environmental cost of using PFAS. Further, fluoropolymers themselves fall under the PFAS umbrella. Here, alternative mechanical-to-electrical energy harvesting polymers are reviewed and benchmarked against the leading fluoropolymer energy harvesters. These alternative technologies include nonfluoropolymer piezoelectric polymers, triboelectric nanogenerators (TENGs), ferroelectric elastomers, and flexoelectric polymers. A vision towards sustainable, non-fluoropolymer-based energy harvesting is provided.

Doping Effects and Relationship between Energy Band Gaps, Impact of Ionization Coefficient and Light Absorption Coefficient in Semiconductors

The doping process is very important in semiconductor technology that is widely used in the production of electronic devices. The effects of doping on the resistivity, mobility and energy band gap of semiconductors are significant and can greatly impact the performance of electronic devices. This thesis aims to investigate the impact of doping on the resistivity, mobility, energy band gap, impact of ionization coefficient, and light absorption coefficient of semiconductors. The study involves an in-depth analysis of the electronic properties of doped semiconductors and their behavior in various conditions. This thesis will provide a comprehensive understanding of the impact of doping on the electronic properties of semiconductors. The energy band gap, impact of ionization coefficient, and Light absorption coefficient were observed in this thesis. In the experimental result, the relation between energy band gap and atomic density, light absorption coefficient and atomic density, impact ionization and atomic density, impact ionization coefficient and Light absorption coefficient, resistivity and mobility has been found.

Synthesis and Characterization of New Hybrid Organic-Inorganic Metal Halides [(CH3)3SO]M2I3 (M = Cu and Ag).

Recently, all-inorganic copper(I) metal halides have emerged as promising optical materials due to their high light emission efficiencies. This work details the crystal structure of the two hybrid organic-inorganic metal halides [(CH3)3SO]M2I3 (M = Cu and Ag) and their alloyed derivatives [(CH3)3SO]Cu2-xAgxI3 (x = 0.2; 1.25), which were obtained by incorporating trimethylsulfoxonium organic cation (CH3)3SO+ in place of Cs+ in the yellow-emitting all-inorganic CsCu2I3. These compounds are isostructural and centrosymmetric with the space group Pnma, featuring one-dimensional edge-sharing [M2I3]- anionic double chains separated by rows of (CH3)3SO+ cations. Based on density functional theory calculations, the highest occupied molecular orbitals (HOMOs) of [(CH3)3SO]M2I3 (M = Cu and Ag) are dominated by the Cu or Ag d and I p orbitals, while the lowest unoccupied molecular orbitals (LUMOs) are Cu or Ag s and I p orbitals. [(CH3)3SO]Cu2I3 single crystals exhibit a semiconductor resistivity of 9.94 × 109 Ω·cm. Furthermore, a prototype [(CH3)3SO]Cu2I3 single-crystal-based X-ray detector with a detection sensitivity of 200.54 uCGy-1 cm-2 (at electrical field E = 41.67 V/mm) was fabricated, indicating the potential use of [(CH3)3SO]Cu2I3 for radiation detection applications.

Ni-doped Co3O4 the influence of different exposed crystal facets and doping amount on the humidity sensitivity: Experiment and theory

Water vapor causes the baseline resistance, response, recovery time, and long-term stability of the metal oxide semiconductor (MOS) gas sensors to change in different humidity. Combining first-principle and experimental can provide an in-depth understanding of the sensing mechanism from the atomic and molecular scales. In this work, we examined the humidity sensitivity of different concentrations of Ni-doped Co3O4 in detail. Co48O64 (110) and Co48O64(111) were constructed by HR-TEM and doped with single, double, and treble Ni atoms on both surfaces. We calculated the adsorption of water and n-butanol molecule on these eight surfaces. The results show that Ni doping improves the moisture resistance properties of Co48O64 (110) and Co48O64(111), and the sensing properties of C3H9OH adsorbed on Ni2Co46O64 (110) and Ni2Co46O64(111) are higher than single and treble Ni atoms doping. To investigate the humidity sensitivity further, we synthesized nanorods Co3O4 with and without Ni doping. The experimental results showed that the humidity sensitivity of Ni-Co3O4 was significantly lower than that of Co3O4. The decrease in the response value for the C3H9OH may be attributed to the change in the concentration of the Ni doping or the difference in the primarily exposed crystal facet.

Structural and Physical Properties of Two Distinct 2D Lead Halides with Intercalated Cu(II).

Transition metal cation intercalation between the layers of two-dimensional (2D) metal halides is an underexplored research area. In this work we focus on the synthesis and physical property characterizations of two layered hybrid lead halides: a new compound [Cu(O2C-CH2-NH2)2]Pb2Br4 and the previously reported [Cu(O2C-(CH2)3-NH3)2]PbBr4. These compounds exhibit 2D layered crystal structures with incorporated Cu2+ between the metal halide layers, which is achieved by combining Cu(II) and lead bromide with suitable amino acid precursors. The resultant [Cu(O2C-(CH2)3-NH3)2]PbBr4 adopts a 2D layered perovskite structure, whereas the new compound [Cu(O2C-CH2-NH2)2]Pb2Br4 crystallizes with a new structure type based on edge-sharing dodecahedral PbBr5O3 building blocks. [Cu(O2C-CH2-NH2)2]Pb2Br4 is a semiconductor with a bandgap of 3.25 eV. It shows anisotropic charge transport properties with a semiconductor resistivity of 1.44×1010 Ω·cm (measured along the a-axis) and 2.17×1010 Ω·cm (along the bc-plane), respectively. The fabricated prototype detector based on this material showed response to soft low-energy X-rays at 8 keV with a detector sensitivity of 1462.7 μCGy-1cm-2, indicating its potential application for ionizing radiation detection. These encouraging results are discussed together with the results from density functional theory calculations, optical, magnetic, and thermal property characterization experiments.

Photoinduced Current Transient Spectroscopy on Metal Halide Perovskites: Electron Trapping and Ion Drift.

Metal halide perovskites (MHPs) are disruptive materials for a vast class of optoelectronic devices. The presence of electronic trap states has been a tough challenge in terms of characterization and thus mitigation. Many attempts based on electronic spectroscopies have been tested, but due to the mixed electronic-ionic nature of MHP conductivity, many experimental results retain a large ambiguity in resolving electronic and ionic charge contributions. Here we adapt a method, previously used in highly resistive inorganic semiconductors, called photoinduced current transient spectroscopy (PICTS) on lead bromide 2D-like ((PEA)2PbBr4) and standard "3D" (MAPbBr3) MHP single crystals. We present two conceptually different outcomes of the PICTS measurements, distinguishing the different electronic and ionic contributions to the photocurrents based on the different ion drift of the two materials. Our experiments unveil deep level trap states on the 2D, "ion-frozen" (PEA)2PbBr4 and set new boundaries for the applicability of PICTS on 3D MHPs.

VLSI Implementation of Hybrid Memristor Based Logic Gates

Practical memristors have gained attention from researchers and scientists due to their potential use in a variety of electronic circuits and devices. In our paper, a hybrid Memristor-CMOS (MeMOS) logic circuit was designed and its transient response was analyzed. This circuit, which uses a N-type metal oxide semiconductor (NMOS), and P-type metal oxide semiconductor (PMOS) transistors, Operational amplifiers (OPAMPs), resistors, capacitors and multipliers replicate memristor characteristics. To facilitate the development of real memristor circuit applications, a memristor emulator is utilized for breadboard experiments. This emulator can be connected in a variety of configurations, including serial, parallel, or a combination of both, with identical or opposite polarities. By simply changing the connection, the emulator can be switched between decremental and incremental configurations. In our paper, we implemented AND logic using MeMOS. PSpice simulation of the proposed emulator have been demonstrated for TiO2 memristor model.

Water-soluble pristine C60 fullerenes attenuate isometric muscle force reduction in a rat acute inflammatory pain model

BackgroundBeing a scavenger of free radicals, C60 fullerenes can influence on the physiological processes in skeletal muscles, however, the effect of such carbon nanoparticles on muscle contractility under acute muscle inflammation remains unclear. Thus, the aim of the study was to reveal the effect of the C60 fullerene aqueous solution (C60FAS) on the muscle contractile properties under acute inflammatory pain.MethodsTo induce inflammation a 2.5% formalin solution was injected into the rat triceps surae (TS) muscle. High-frequency electrical stimulation has been used to induce tetanic muscle contraction. A linear motor under servo-control with embedded semi-conductor strain gauge resistors was used to measure the muscle tension.ResultsIn response to formalin administration, the strength of TS muscle contractions in untreated animals was recorded at 23% of control values, whereas the muscle tension in the C60FAS-treated rats reached 48%. Thus, the treated muscle could generate 2-fold more muscle strength than the muscle in untreated rats.ConclusionsThe attenuation of muscle contraction force reduction caused by preliminary injection of C60FAS is presumably associated with a decrease in the concentration of free radicals in the inflamed muscle tissue, which leads to a decrease in the intensity of nociceptive information transmission from the inflamed muscle to the CNS and thereby promotes the improvement of the functional state of the skeletal muscle.

ДИЭЛЕКТРИКТЕРДІҢ ЭЛЕКТРЛІК БЕРІКТІГІ

Abstract. In human life, even in practice, solids play an important role. Metals, dielectrics, electrical engineering, semiconductors, electrons, magnets, conductors lying close to each other are all solids. It can be argued that the basis for the foundation of scientific and technological progress is a solid body. But in their study, not only practical activity mattered. For its subsystems of development, solid state physics has opened a scientific path to understanding the properties of importance. all materials used in engineering are divided into three groups: conductors, semiconductors and dielectrics. These materials differ in the magnitude of electrical resistance, the nature of its changes during heating and the type of conductivity.The electrical resistivity of the conductors is in the range of 10-6 + 10-3 oms • cm and is used as a material with a small intermediate electrical resistance for resistance elements, heating elements, contacts, etc. for conducting constant and rotational currents. Electrical resistivity of semiconductors 10-3+10+10 Om* is within cm and decreases when heated. They are used for rectification, amplification, conversion of various types of energy into electricity. Electrical resistivity of dielectrics 10+10+10+18 Oms* are within cm, they are used as insulators. The conductivity of solids is determined primarily by the electronic structure. In solids, as a result of the interaction of the electromagnetic field of atoms, energy electronic sublevels are classified with the formation of an energy zone [1]. With the transition to a higher energy, the width of the zone of permissible sublevels increases, and the zones intersect. When approaching the distance between atoms Forbidden energy zones even disappear. The density of the zones filled with electrons and their crosslinking determine the electrical conductivity of solids. Keywords: dielectric, composition, automation, electronics, radio engineering, aerospace, rocket, electrical, conductor.

Multichannel Generator Time-To-Pulse Converter of the Telemetry Temperature Measurement System

The article considers the multichannel time-to-pulse intermediate converter as a part of telemetric temperature measurement system. The principle of operation is based on the use of aperiodic transient in a first-order circuit formed by resistance temperature device and capacitor. Switching of resistance temperature device in the process of temperature measurements is carried out by MIS keys (metal-insulator-semiconductor) according to the signal from the output of the circuit, and the allocation of the output information interval is carried out by a voltage comparator. The article illustrates an electric circuit of a time-to-pulse converter. Based on the equivalent scheme, the main metrological characteristics were obtained by calculation, namely, the dependences of the sensitivity of the output value of the converter to changes in the parameters of the circuit elements expressed in terms of temperature. The scheme of a time-to-pulse converter with an optical output, designed for use with semiconductor resistance temperature devices was experimentally investigated. Variants of multichannel converters for 7 and 15 measuring channels are implemented. Digital elements of the MIS-type (metal-insulator-semiconductor) are used. Information about the temperature at the output of the converters was encoded in the duration of 128 periods of pulse signals, which ensured reliable of information intervals in the receiving part of the equipment. A laboratory tester with an optoelectronic input was used as a receiver of optical pulses. The duration of the information intervals was measured by an industrial measuring device with a resolution of 10 billiseconds. The experimental and rated characteristics of the conversion and the dependence of the conversion error on the supply voltage, operating temperature and resistance of primary thermal converters are presented. It is established that in terms of the main operational parameters, a generator-type time-to-pulse converter is not inferior to a circuit with external excitation. At the same time, the generator converter is less sensitive to the errors of the comparator in terms of electrical bias and speed. The use of a multichannel generator time-to-pulse converter is advisable in telemetric temperature measurement systems when transmitting information in a communication channel during the duration of the period of information, in particular, optical pulses.

Highly Efficient NO2 Sensors Based on Al-ZnOHF under UV Assistance.

Zinc hydroxyfluoride (ZnOHF) is a newly found resistive semiconductor used as a gas-sensing material with excellent selectivity to NO2 because of its unique energy band structure. In this paper, Al3+ doping and UV radiation were used to further improve the gas-sensing performance of ZnOHF. The optimized 0.5 at.% Al-ZnOHF sample exhibits improved sensitivity to 10 ppm NO2 at a lower temperature (100 °C) under UV assistance, as well as a short response/recovery time (35 s/96 s). The gas-sensing mechanism demonstrates that Al3+ doping increases electron concentration and promotes electron transfer of the nanorods by reducing the bandgap of ZnOHF, and the photogenerated electrons and holes with high activity under UV irradiation provide new reaction routes in the gas adsorption and desorption process, effectively promoting the gas-sensing process. The synergistic effect of Al3+ and UV radiation contribute to the enhanced performance of Al-ZnOHF.