Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 15 de 15
Filter
Add more filters










Publication year range
1.
Micromachines (Basel) ; 14(3)2023 Mar 10.
Article in English | MEDLINE | ID: mdl-36985040

ABSTRACT

In this work, a new low voltage-triggered silicon-controlled rectifier named MTSCR is realized in a 65 nm CMOS process for low voltage-integrated circuits electrostatic discharge (ESD) protections. The MTSCR incorporates an external NMOSs-string, which drives the internal NMOS (INMOS) of MTSCR to turn on, and then the INMOS drive SCR structure to turn on. Compared with the existing low trigger voltage (Vt1) ESD component named diodes-string-triggered SCR (DTSCR), the MTSCR can realize the same low Vt1 characteristic but less area penalty of ~44.3% reduction. The results of the transmission line pulsing (TLP) measurement shows that the MTSCR possesses above 2.42 V holding voltage (Vh) and a low Vt1 of ~5.03 V, making it very suitable for the ESD protections for 1.8 V input/output (I/O) ports in CMOS technologies.

2.
Small ; 19(19): e2207927, 2023 May.
Article in English | MEDLINE | ID: mdl-36748299

ABSTRACT

In this work, monolithic three-dimensional complementary metal oxide semiconductor (CMOS) inverter array has been fabricated, based on large-scale n-MoS2 and p-MoTe2 grown by the chemical vapor deposition method. In the CMOS device, the n- and p-channel field-effect transistors (FETs) stack vertically and share the same gate electrode. High k HfO2 is used as the gate dielectric. An Al2 O3 seed layer is used to protect the MoS2 from heavily n-doping in the later-on atomic layer deposition process. P-MoTe2 FET is intentionally designed as the upper layer. Because p-doping of MoTe2 results from oxygen and water in the air, this design can guarantee a higher hole density of MoTe2 . An HfO2 capping layer is employed to further balance the transfer curves of n- and p-channel FETs and improve the performance of the inverter. The typical gain and power consumption of the CMOS devices are about 4.2 and 0.11 nW, respectively, at VDD of 1 V. The statistical results show that the CMOS array is with high device yield (60%) and an average voltage gain value of about 3.6 at VDD of 1 V. This work demonstrates the advantage of two-dimensional semi-conductive transition metal dichalcogenides in fabricating high-density integrated circuits.

3.
ACS Appl Mater Interfaces ; 14(36): 41508-41519, 2022 Sep 14.
Article in English | MEDLINE | ID: mdl-36066003

ABSTRACT

Thin-film transistor (TFT) is a essential device for future electronics driving the next level of digital transformation. The development of metal-oxide-semiconductor (MOS) TFTs is considered one of the most advantageous devices for next-generation, large-area flexible electronics. This study demonstrates the systematic study of the amorphous gallium oxide (a-Ga2O3) and its application to nanocrystalline ZnO TFTs. The TFT with a-Ga2O3/c-ZnO-stack channel exhibits a field-effect mobility of ∼41 cm2 V-1 s-1 and excellent stability under positive-bias-temperature stress. The a-Ga2O3/c-ZnO-stack TFT on polyimide (PI) substrate exhibits a negligible threshold voltage shift upon 100k bending cycles with a radius of 3 mm and is very stable under environmental test. The smooth morphology with tiny grains of ∼12 nm diameter with fewer grain boundary states improves the charge transport in Ga2O3/ZnO-stack TFT. The existence of amorphous a-Ga2O3 in between very thin ZnO layers helps to enhance the heterointerfaces and reduce the defect density in Ga2O3/ZnO interface. Therefore, integrating a-Ga2O3 in the ZnO channel in stacked TFT can increase mobility and enhance stability for next-generation flexible TFT electronics.

4.
Adv Mater ; 34(48): e2202472, 2022 Dec.
Article in English | MEDLINE | ID: mdl-35728050

ABSTRACT

2D semiconductors, such as molybdenum disulfide (MoS2 ), have attracted tremendous attention in constructing advanced monolithic integrated circuits (ICs) for future flexible and energy-efficient electronics. However, the development of large-scale ICs based on 2D materials is still in its early stage, mainly due to the non-uniformity of the individual devices and little investigation of device and circuit-level optimization. Herein, a 4-inch high-quality monolayer MoS2 film is successfully synthesized, which is then used to fabricate top-gated (TG) MoS2 field-effect transistors with wafer-scale uniformity. Some basic circuits such as static random access memory and ring oscillators are examined. A pass-transistor logic configuration based on pseudo-NMOS is then employed to design more complex MoS2 logic circuits, which are successfully fabricated with proper logic functions tested. These preliminary integration efforts show the promising potential of wafer-scale 2D semiconductors for application in complex ICs.

5.
Micromachines (Basel) ; 13(2)2022 Feb 04.
Article in English | MEDLINE | ID: mdl-35208382

ABSTRACT

In this article, we present the design, fabrication, and characterization of a thermopile infrared sensor array (TISA) pixel. This TISA pixel is composed of a dual-layer p+/n- poly-Si thermopile with a closed membrane and an n-channel metal oxide semiconductor (NMOS) switch. To address the challenges in fabrication through the 3D integration method, the anode of the thermopile is connected to the drain of the NMOS, both of which are fabricated on the same bulk wafer using a CMOS compatible monolithic integration process. During a single process sequence, deposition, etching, lithography, and ion implantation steps are appropriately combined to fabricate the thermopile and the NMOS simultaneously. At the same time as ensuring high thermoelectric characteristics of the dual-layer p+/n- poly-Si thermopile, the basic switching functions of NMOS are achieved. Compared with a separate thermopile, the experimental results show that the thermopile integrated with the NMOS maintains a quick response, high sensitivity and high reliability. In addition, the NMOS employed as a switch can effectively and quickly control the readout of the thermopile sensing signal through the voltage, both on and off, at the gate of NMOS. Thus, such a TISA pixel fabricated by the monolithic CMOS-compatible integration approach is low-cost and high-performance, and can be applied in arrays for high-volume production.

6.
Rev. neurol. (Ed. impr.) ; 74(1): 22-34, Ene 1, 2022. tab, mapas
Article in English, Spanish | IBECS | ID: ibc-217558

ABSTRACT

Introducción: La presente revisión epidemiológica sobre el espectro de neuromielitis óptica (NMOSD) se focaliza en la descripción metodológica de los estudios realizados bajo los criterios del NMOSD de 2015, en la descripción de estudios realizados en España y Latinoamérica, así como en los factores relacionados con el pronóstico de la enfermedad. Desarrollo: La metodología utilizada en los estudios varía fundamentalmente en la aplicación de diferentes criterios diagnósticos, fuentes de registros, técnicas de detección de anticuerpos y métodos de estandarización. Sin embargo, en términos generales, el NMOSD tiene una distribución mundial con una mayor incidencia/prevalencia en las mujeres que en los hombres, y en los países asiáticos y afroamericanos que en los países occidentales. La frecuencia aumenta de manera paralela a la edad, con un pico de incidencia/prevalencia en el rango entre 40 y 59 años. La población latinoamericana presenta unas características epidemiológicas particulares ligadas a su mezcla racial y genética. Finalmente, variables epidemiológicas, como la raza negra, una mayor edad en el inicio y el sexo femenino, se asocian a un peor pronóstico funcional. Conclusiones: Los datos epidemiológicos del NMOSD varían entre los diferentes estudios, debido, en gran parte, a discrepancias en los diseños metodológicos. Aunque son escasos los estudios latinoamericanos, los hallazgos descritos se asocian a su mezcla étnica. La homogeneización de criterios, utilización de técnicas diagnósticas y métodos de estandarización similares es de fundamental aplicación para el correcto estudio de la epidemiología del NMOSD.


Introduction: This epidemiological review on neuromyelitis optica spectrum disorder (NMOSD) focuses on describing the methodologies employed in studies conducted under the 2015 NMOSD criteria and the studies conducted in Spain and Latin America, as well as examining factors related to the prognosis of the disease. Development: The methodology used in the studies varies essentially in the application of different diagnostic criteria, sources of records, antibody detection techniques and standardisation methods. However, in general terms, NMOSD is distributed worldwide with an incidence/prevalence that is higher in women than in men, and in Asian and African-American countries than in Western countries. The frequency increases in parallel to age, with a peak incidence/prevalence in the 40-59 age range. The Latin American population has particular epidemiological characteristics linked to its racial and genetic mix. Finally, epidemiological variables, such as belonging to the black race, being of older age at onset and being female, are associated with a worse functional prognosis. Conclusions: Epidemiological data on NMOSD vary from one study to another, largely due to discrepancies in the methodological designs. Although Latin American studies are scarce, the findings described are associated with their ethnic mix. The homogenisation of criteria and the use of similar diagnostic techniques and standardisation methods must be implemented for the correct study of the epidemiology of NMOSD.(AU)


Subject(s)
Humans , Male , Female , Neuromyelitis Optica/epidemiology , Aquaporin 4 , Antibodies , Spain , Latin America , Neurology
7.
ACS Appl Mater Interfaces ; 13(51): 61544-61554, 2021 Dec 29.
Article in English | MEDLINE | ID: mdl-34910468

ABSTRACT

Polarization-sensitive photodetection is highly appealing considering its great important applications. However, the inherent in-plane symmetry of a material and the single structure of a detector hinder the further development of polarization detectors with high anisotropic ratios. Herein, we design a p-WSe2/TaIrTe4/n-MoS2 (p-Ta-n) heterojunction. As a type-II Weyl semimetal, TaIrTe4 with an orthorhombic structure has strong in-plane asymmetry, which is confirmed by angle-resolved polarized Raman spectroscopy and second-harmonic generation. Due to the specific structure of the p-Ta-n junction with two vertical built-in electric fields, the device obtains a broadband self-powered photodetection ranging from visible (405 nm) to telecommunication wavelength (1550 nm) regions. Further, an optimized device containing 50-70 nm-thick layered TaIrTe4 has been realized. What is more, high-resolution imaging of "T" based on the device with clear borders illustrates excellent stability of the device. Significantly, the photocurrent anisotropic ratio of the p-Ta-n detector can reach 9.1 under 635 nm light, which is more than eight times that of the best known TaIrTe4-based photodetector reported before. This p-Ta-n junction containing a type-II Weyl fermion semimetal can provide an effective approach toward highly polarization-sensitive and high-performance integrated broadband photodetectors.

8.
Nanomicro Lett ; 13(1): 164, 2021 Aug 03.
Article in English | MEDLINE | ID: mdl-34342729

ABSTRACT

Metal oxide thin-films transistors (TFTs) produced from solution-based printing techniques can lead to large-area electronics with low cost. However, the performance of current printed devices is inferior to those from vacuum-based methods due to poor film uniformity induced by the "coffee-ring" effect. Here, we report a novel approach to print high-performance indium tin oxide (ITO)-based TFTs and logic inverters by taking advantage of such notorious effect. ITO has high electrical conductivity and is generally used as an electrode material. However, by reducing the film thickness down to nanometers scale, the carrier concentration of ITO can be effectively reduced to enable new applications as active channels in transistors. The ultrathin (~10-nm-thick) ITO film in the center of the coffee-ring worked as semiconducting channels, while the thick ITO ridges (>18-nm-thick) served as the contact electrodes. The fully inkjet-printed ITO TFTs exhibited a high saturation mobility of 34.9 cm2 V-1 s-1 and a low subthreshold swing of 105 mV dec-1. In addition, the devices exhibited excellent electrical stability under positive bias illumination stress (PBIS, ΔVth = 0.31 V) and negative bias illuminaiton stress (NBIS, ΔVth = -0.29 V) after 10,000 s voltage bias tests. More remarkably, fully printed n-type metal-oxide-semiconductor (NMOS) inverter based on ITO TFTs exhibited an extremely high gain of 181 at a low-supply voltage of 3 V, promising for advanced electronics applications.

9.
Mater Sci Eng C Mater Biol Appl ; 112: 110898, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32409055

ABSTRACT

Nitrogen-doped MoS2 quantum dots (N-MoS2 QDs) were synthesized via a facile hydrothermal approach, and exhibited high fluorescence quantum yield (QY, 14.9%), excellent photostability, biocompatibility and water solubility. A novel method with good selectivity and sensitivity was established to assay hematin using N-MoS2 QDs as a fluorescent probe based on inner filter effect (IFE). Fluorescent quenching of N-MoS2 QDs has a fine linear dependence with the concentration of hematin in the range of 0.5-15 µmol/L and a limit of detection of 0.32 µmol/L (S/N = 3). By the detection method, average concentration of hematin in real health human erythrocytes was measured as 22.5 ± 3.9 µmol/L. And, recoveries range varied from 94 to 108% through standard recovery experiment. The N-MoS2 QDs probe shows excellent photostability, low cytotoxicity and anti-interference ability for hematin assay, which may become a promising method for the test of hematin in human blood.


Subject(s)
Disulfides/chemistry , Hemin/analysis , Molybdenum/chemistry , Nitrogen/chemistry , Quantum Dots/chemistry , Spectrometry, Fluorescence/methods , A549 Cells , Cell Survival/drug effects , Erythrocytes/metabolism , Fluorescent Dyes/chemistry , Humans , Limit of Detection , Microscopy, Fluorescence , Quantum Dots/toxicity , Solubility
10.
Materials (Basel) ; 13(8)2020 Apr 16.
Article in English | MEDLINE | ID: mdl-32316301

ABSTRACT

Cu3N/MoS2 heterojunction was prepared through magnetron sputtering, and its optical band gap was investigated. Results showed that the prepared Cu3N/MoS2 heterojunction had a clear surface heterojunction structure, uniform surface grains, and no evident cracks. The optical band gap (1.98 eV) of Cu3N/MoS2 heterojunction was obtained by analyzing the ultraviolet-visible transmission spectrum. The valence and conduction band offsets of Cu3N/MoS2 heterojunction were 1.42 and 0.82 eV, respectively. The Cu3N film and multilayer MoS2 formed a type-II heterojunction. After the two materials adhered to form the heterojunction, the interface electrons flowed from MoS2 to Cu3N because the latter had higher Fermi level than the former. This behavior caused the formation of additional electrons in the Cu3N and MoS2 layers and the change in optical band gap, which was conducive to the charge separation of electrons in MoS2 or MoS2 holes. The prepared Cu3N/MoS2 heterojunction has potential application in various high-performance photoelectric devices, such as photocatalysts and photodetectors.

11.
Cell Stem Cell ; 26(2): 172-186.e6, 2020 02 06.
Article in English | MEDLINE | ID: mdl-31956040

ABSTRACT

Neuromuscular networks assemble during early human embryonic development and are essential for the control of body movement. Previous neuromuscular junction modeling efforts using human pluripotent stem cells (hPSCs) generated either spinal cord neurons or skeletal muscles in monolayer culture. Here, we use hPSC-derived axial stem cells, the building blocks of the posterior body, to simultaneously generate spinal cord neurons and skeletal muscle cells that self-organize to generate human neuromuscular organoids (NMOs) that can be maintained in 3D for several months. Single-cell RNA-sequencing of individual organoids revealed reproducibility across experiments and enabled the tracking of the neural and mesodermal differentiation trajectories as organoids developed and matured. NMOs contain functional neuromuscular junctions supported by terminal Schwann cells. They contract and develop central pattern generator-like neuronal circuits. Finally, we successfully use NMOs to recapitulate key aspects of myasthenia gravis pathology, thus highlighting the significant potential of NMOs for modeling neuromuscular diseases in the future.


Subject(s)
Organoids , Pluripotent Stem Cells , Female , Humans , Neuromuscular Junction , Pregnancy , Reproducibility of Results , Spinal Cord
12.
Sensors (Basel) ; 19(19)2019 Sep 25.
Article in English | MEDLINE | ID: mdl-31557820

ABSTRACT

Micromachined gyroscopes require high voltage (HV) for actuation and detection to improve its precision, but the deviation of the HV caused by temperature fluctuations will degrade the sensor's performance. In this paper, a high-voltage temperature-insensitive charge pump is proposed. Without adopting BCD (bipolar-CMOS-DMOS) technology, the output voltage can be boosted over the breakdown voltage of n-well/substrate diode using triple-well NMOS (n-type metal-oxide-semiconductor) transistors. By controlling the pumping clock's amplitude continuously, closed-loop regulation is realized to reduce the output voltage's sensitivity to temperature changes. Besides, the output level is programmable linearly in a large range by changing the reference voltage. The whole circuit has been fabricated in a 0.18- µ m standard CMOS (complementary metal-oxide-semiconductor) process with a total area of 2.53 mm 2 . Measurements indicate that its output voltage has a linear adjustable range from around 13 V to 16.95 V, and temperature tests show that the maximum variations of the output voltage at - 40 ∼ 80 ∘ C are less than 1.1%.

13.
Micromachines (Basel) ; 9(12)2018 Dec 14.
Article in English | MEDLINE | ID: mdl-30558147

ABSTRACT

In this paper, for the first time, an n-channel metal-oxide-semiconductor field-effect transistor (NMOSFET) layout with a Z gate and an improved total ionizing dose (TID) tolerance is proposed. The novel layout can be radiation-hardened with a fixed charge density at the shallow trench isolation (STI) of 3.5 × 1012 cm-2. Moreover, it has the advantages of a small footprint, no limitation in W/L design, and a small gate capacitance compared with the enclosed gate layout. Beside the Z gate layout, a non-radiation-hardened single gate layout and a radiation-hardened enclosed gate layout are simulated using the Sentaurus 3D technology computer-aided design (TCAD) software. First, the transfer characteristics curves (Id-Vg) curves of the three layouts are compared to verify the radiation tolerance characteristic of the Z gate layout; then, the threshold voltage and the leakage current of the three layouts are extracted to compare their TID responses. Lastly, the threshold voltage shift and the leakage current increment at different radiation doses for the three layouts are presented and analyzed.

14.
Bioresour Technol ; 144: 477-84, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23890975

ABSTRACT

A novel and robust distributed benthic microbial fuel cell (DBMFC) was developed to address the energy supply issues for oceanographic sensor network applications, especially under scouring and bioturbation by aquatic life. Multi-anode/cathode configuration was employed in the DBMFC system for enhanced robustness and stability in the harsh ocean environment. The results showed that the DBMFC system achieved peak power and current densities of 190mW/m(2) and 125mA/m(2) respectively. Stability characterization tests indicated the DBMFC with multiple anodes achieved higher power generation over the systems with single anode. A computational model that integrated physical, electrochemical and biological factors of MFCs was developed to validate the overall performance of the DBMFC system. The model simulation well corresponded with the experimental results, and confirmed the hypothesis that using a multi anode/cathode MFC configuration results in reliable and robust power generation.


Subject(s)
Bioelectric Energy Sources , Models, Theoretical , Electricity , Electrochemical Techniques , Electrodes , Reproducibility of Results , Thermodynamics
15.
Adv Mater ; 25(32): 4445-51, 2013 Aug 27.
Article in English | MEDLINE | ID: mdl-23784849

ABSTRACT

A metal-cluster-decoration approach is utilized to tailor electronic transport properties (e.g., threshold voltage) of III-V NWFETs through the modulation of free carriers in the NW channel via the deposition of different metal clusters with different work function. The versatility of this technique has been demonstrated through the fabrication of high-mobility enhancement-mode InAs NW parallel FETs as well as the construction of low-power InAs NW inverters.

SELECTION OF CITATIONS
SEARCH DETAIL
...