Post Oxide Research Articles

A facile route derived solar selective nickel-cobalt oxide thin films via spraying process

Abstract This work focuses on understanding the role of annealing temperature on the solar selective performance of nickel-cobalt oxide thin films successfully sprayed onto Al substrates using the spray pyrolysis technique. The synthesized nickel-cobalt oxide thin films (~ 725± 20 nm thick) were post annealed at (400, 500 and 600) °C. The XRD and FESEM outcomes appeared high crystalline quality with crystal grains in the range of (27 – 52) nm and improved surface morphology for the sprayed thin films. The optical properties reflect solar absorptance ~ (85.2 %) and the thermal emittance ~ (4.45 %). The hardness and the Young’s modulus were (19.1 GPa) and (104 GPa) respectively. The aforementioned results are for the film annealed at 600 °C. The prepared and post annealed nickel-cobalt oxide thin films show band gap energies in the range of (1.15 – 1.38) eV. The nickel-cobalt oxide thin films also possess excellent thermal stability at higher temperature which makes them interesting candidate for solar absorbing and thermal collector applications.

Deciphering Vascular Dynamics Alterations in Sub-Saharan Individuals with Type 2 Diabetes: Overview and Temporal Analysis of Nitric Oxide Administration

Background: Early detection of arterial damage is essential for the primary prevention of complications linked to type 2 diabetes (T2D). The study assessed the cardiovascular risk of sub-Saharan African individuals with T2D, while exploring possible mechanisms involved in the pathogenesis of vascular complications in this population. Methodology: A crossover study of 72 sub-Saharan African adults (36 with T2D and 36 without T2D) was conducted. Outcomes including diameter size (mm) and blood velocity (cm/s) of the brachial artery, were obtained at seven time points: baseline and from 5 seconds to 600 seconds in two conditions: pre- and post Nitric Oxide (NO) administration. HbA1C, fasting glucose, age, BMI, mean arterial pressure (MAP), lipid profile, T2D duration since diagnosis, and binary indicators of insulin and oral diabetes medication were evaluated. Results: NO improved the blood flow compared to the pre-NO after adjustment for clinical factors. The beneficial effect of NO administration on vascular dynamics was influenced by age (<I>B</I>=1.09; 95%IC: 1.07, 1.11), increased BMI (<I>B</I>= 1.03; 95%IC: 1.01, 1.04) and insulin use (<I>B</I> = 1.13; 95%IC 1.10, 1.16). Conclusion: The nuanced impact of these factors on blood flow improvement related to NO necessitates tailored and personalized approaches in managing T2D patients.

Evolution of Interface State Density and Near Interface Oxide Traps under Controlled Nitric Oxide Annealing in SiO<sub>2</sub>/SiC Lateral MOSFETs

In this paper, the effect of different post oxide deposition nitridation processes in NO on n-channel lateral MOSFETs fabricated on implanted 4H-SiC were investigated. In particular, the electrical behavior of the MOSFETs was deeply investigated not only in terms of SiO2/SiC interface state density and field effect mobility, but also considering the threshold voltage stability effect. The aim of this work was to explore to which extent post oxide deposition annealing in NO is beneficial for the MOS interface behavior and when their detrimental effects start to become predominant on the device performances. Here, the separation of the trapping states at the interface – either close to the conduction and valence band edges – and the near interface oxide traps are reported for the different duration of the post oxide deposition annealing. In fact, cyclic gate bias stress was employed in order to analyze the behavior of the trapping states and to correlate them with the variation of the benefits in terms of the channel mobility (that saturates at about 80 cm2V-1s-1), and on the threshold voltage instability effect. In particular, prolonged PDAs may induce an increase of the amount of trapping states close to the valence band edge and inside the insulator of about 20% and 50 %, respectively.

Enhanced Linearity in CBRAM Synapse by Post Oxide Deposition Annealing for Neuromorphic Computing Applications

Artificial synapse with good linearity is a critical issue in conductive bridging random access memory (CBRAM) synaptic device to accomplish an efficient learning approach in the artificial intelligence system. In this work, we investigate a novel approach to enhance the linearity of CBRAM synapse. The linearity of a memristive synapse can be improved by the high-temperature vacuum annealing process. The annealed device not only improves reliability such as endurance characteristics but also improves the synaptic characteristics including multilevel characteristics with varying RESET stop voltages from −0.60 to −1.40 V. The nonlinearities of potentiation and depression are 1.36 and −2.18 with 500 conductance pulses, respectively, and the device exhibits 720 training epochs with a total number of 720 000 pulse numbers. The post oxide annealed CBRAM device with analog switching behavior and excellent reliability is potential to be an artificial synapse for neuromorphic computing. In addition, the experimental potentiation and depression data are employed to train HNN for image processing of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$30\times30$ </tex-math></inline-formula> pixels comprising 900 synapses. It is found that the HNN can be successfully trained to recognize the input image with a training accuracy of ~98% in 18 iterations.

What We Currently Know about Carbon‐Supported Metal and Metal Oxide Nanomaterials in Electrochemical CO2 Reduction

AbstractElectrochemical reduction of CO2 is considered important in enhancing the circular‐economy design; it can suppress harmful greenhouse‐gas emissions while, combined with intermittent renewable energy sources, it can employ the surplus energy for production of important chemicals and fuels. In the process, electrocatalysts play an important role as the mediators of the highly active and selective conversion of CO2. Transition and post transition metals and their oxides are an important electrocatalyst group. For practical reasons, these metals need to be applied as nanoparticles supported on highly conducting materials enabling fabrication of 3D electrodes. In this minireview, we focus on gathering our current knowledge on the effects which transition and post transition metal and metal oxide nanoparticles supported on different carbons may have on electrochemical reduction of CO2. We focus on literature of studies conducted in aqueous conditions, under as similar conditions as possible, to ensure comparability. This approach enables us to highlight possible support effects and issues that complicate making conclusions on support effects.

Effect of annealing temperature on the electrical and photoluminascence properties of tin oxide thin films prepared by sol-gel spin coating technique

Tin oxide thin films were sucessfully synthesized by sol–gel spin coating technique using SnCl2·2H2O and Ethanol as precurser. The prepared films were post annealed at different temperatures such as 300, 400, 500, 600 and 700 °C. The room temperature electrical conductivities of the as prepared and post annealed tin oxide thin films at different temperatures were ranging from 0.0820 × 103 Ω−1 m−1–0.5766 × 103 Ω−1 m−1. The Figure of merit values were calculated and are ranging from 4.3336 × 10−6 Ω−1 –25.0907 × 10−6 Ω−1. PL study shows that an intense and broad blue asymmetric emission band centered at 389 nm.

Turning indium oxide into high-performing electrode materials via cation substitution strategy: Preserving single crystalline cubic structure of 2D nanoflakes towards energy storage devices

Enhancement in electrochemical performance of electrode materials has been the recent focus for material development of electrochemical energy storage devices. For the first time, we turn a post transition metal oxide, indium oxide (In2O3), into a high capacity, excellent stability and rate capability electrode by introducing suitable cations. Various electrode materials M-In2O3 (where M is Co, Fe, Mg, Mn, Ni, and Zn) have been prepared by simple and inexpensive cation substitution route. Among all, the optimal promoter Co–In2O3 electrode deliver higher specific capacity (4.8 times) and rate capability (1.3 times) than bare In2O3. The capacitive contribution and diffusion contribution reactions have been studied for all the electrodes. The capacitive distribution has been increased by Mg and Zn substitution and the diffusion contribution has been enhanced with Co, Fe, Mn, and Ni substitution. Furthermore, structural and electronic properties of In2O3 substituted with the cations have been studied through first principles density functional theory calculations. Moreover, seven asymmetric supercapacitor devices have been assembled by using In2O3 and M-In2O3 as the positive and the reduced graphene oxide as the negative electrode materials. The wrist watch, stop watch, and LEDs have been successfully operated, illustrate the prospective of electrode materials towards practical applications.

&lt;p&gt;Hexagonal Boron Nitrides (White Graphene): A Promising Method for Cancer Drug Delivery&lt;/p&gt;

Advances in low-dimensions nanomaterials drug-carrier have rapidly translated into clinical practice. Interestingly, the two-dimensional (2D) nanomaterials of hexagonal boron nitride (h-BN), so-called “white graphite” are relatively less explored compared to the post popular 2D graphene oxide (GO). However, the unique properties of h-BN nanomaterials make them well suited for the delivery of chemotherapeutic in cancer treatment. Recent studies have shown that the h-BN is a potential candidate in biomedical sciences, both as nanocarriers and nano-transducers. In this review, we discuss the various physicochemical properties and important concepts involved in h-BN nanosheets as anticancer drug carriers.

Effect of Post Oxide Annealing on the Electrical and Interface 4H-SiC/Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; MOS Capacitors

This paper reports on the effect of forming gas annealing on the C-V characteristics and stability of Al2O3/SiC MOS capacitors deposited by atomic layer deposition, (ALD). C-V and I-V measurements were performed to assess the quality of the Al2O3 layer and the Al2O3/SiC interface. In comparison to as-deposited sample, the post oxide annealing (POA) in forming gas at high temperatures has improved the stability of C-V characteristic and the properties at the interface of Al2O3/SiC capacitors. However, the oxide capacitance and oxide breakdown electric field degrade with increased annealing temperature. The results provide indications to improve the performance of Al2O3/SiCcapacitors 4H-SiC devices by optimizing the annealing temperature.

A CMOS Compatible MEMS Pirani Vacuum Gauge with Monocrystal Silicon Heaters and Heat Sinks**Supported by the National High Technology Research and Development Program of China under Grant No 2015AA042602.

We present a micro-Pirani vacuum gauge using the low-resistivity monocrystal silicon as the heaters and heat sinks fabricated by the post complementary metal oxide semiconductor (CMOS) microelectromechanical system (MEMS) process. The metal interconnection of the device is fabricated by a 0.5 μm standard CMOS process on 8-inch silicon wafer. Then, a –Si low-temperature fusion bonding is developed to bond the CMOS wafer and the MEMS wafer, with the electrical connection realized by the tungsten through silicon via process. Wafer-level AlGe eutectic bonding is adopted to package the Pirani gauge in a non-hermetic cavity to protect the gauge from being damaged or contaminated in the dicing and assembling process, and to make it suitable for actual applications. To increase the accuracy of the test and restrain negative influence of temperature drift, the Wheatstone bridge structure is introduced. The test results show that before capping, the gauge has an average sensitivity of 1.04 × K· in dynamic range of 0.01–20 Torr. After capping, the sensitivity of the gauge does not decrease but increases to 1.12 × K· .

Synthesis of magnetron sputtered WO3 nanoparticles-degradation of 2-chloroethyl ethyl sulfide and dimethyl methyl phosphonate

In the present study, tungsten oxide nanoparticles were synthesized using DC magnetron sputtering and investigated their potential for decontamination of 2-chloroethyl ethyl sulfide (CEES) and dimethyl methyl phosphonate (DMMP). The tungsten oxide nanoparticles were characterized by Powder XRD, FE-SEM, EDS, TEM, TGA, N2-BET and FT-IR techniques. The XRD patterns of as-deposited and post annealed tungsten oxide nanoparticles reveal that the crystallite size of detected monoclinic phase WO3 nanoparticle was increased with increasing annealing temperatures. The phase and increase in particles size of WO3 nanoparticles were also confirmed by Raman and TEM analyses. The obtained surface area (∼63–33m2/g) of magnetron sputtered WO3 nanoparticles was found to be enhanced significantly as compared to reported surface area of WO3 nanoparticles synthesis by various techniques. The study of degradation reactions of CEES and DMMP on the surface of obtained nanoparticles was carried out by using GC and GC–MS techniques. The decontamination reactions were found to be pseudo first order steady state with rate constant (k) and half life values 0.143–0.109h−1 and 4.82–6.49h for CEES and 0.018–0.010h−1 and 36.87–66.65h for DMMP, respectively. The FT-IR data reveal the role of hydrolysis reactions in the decontamination of CEES as well as DMMP.

A flexible and implantable microelectrode arrays using high-temperature grown vertical carbon nanotubes and a biocompatible polymer substrate

This paper presents a novel microelectrode arrays using high-temperature grown vertically aligned carbon nanotubes (CNTs) integrated on a flexible and biocompatible parylene substrate. A simple microfabrication process is proposed to unite the high quality vertical CNTs grown at high temperature with the heat sensitive parylene substrate in a highly controllable manner. Briefly, the CNTs electrode is encapsulated by two layers of parylene and the device is released using xenon difluoride (XeF2). The process is compatible with wafer-scale post complementary metal oxide semiconductor integration. Lower impedance and larger interfacial capacitance have been demonstrated using CNTs compared to a Pt electrode. The flexible CNT electrodes have been utilized for extracellular neuronal recording and stimulation in rats. The signal-to-noise ratio of the device is about 12.5. The threshold voltage for initiating action potential is about 0.5 V.

The effect of post oxide deposition annealing on the effective work function in metal/Al2O3/InGaAs gate stack

The effect of post oxide deposition annealing on the effective work function in metal/Al2O3/ InGaAs gate stacks was investigated. Using a systematic method for effective work function extraction, a shift of 0.3 ± 0.1 eV was found between the effective work function of forming gas annealed samples and vacuum annealed samples. The electrical measurements enabled us to obtain the band alignment of the metal/Al2O3/InGaAs gate stack. This band alignment was confirmed by X-ray photoelectron spectroscopy. The measured shift in the effective work function between different annealing ambient may be attributed to indium out-diffusion during post oxide deposition annealing that is observed in forming gas anneal to a much larger extent than in vacuum.

Stack Layer SiO2 / Gd2O3 / SiO2 / GaAs pH-Sensitive Electrolyte Insulator Semiconductor Capacitors and Their Anneal Temperature Dependency

The pH sensing capacitors with stacked oxide layers prepared on compound semiconductor GaAs substrate were fabricated and until recently had been reported on seldom. In this work, the proposed GaAs-based stack layer capacitors with a so-called electrolyte insulator semiconductor (EIS) structure are demonstrated and are easily further integrated with other GaAs-based radio-frequency or light emitting devices to construct an integrated multifunction sensor in the future. Among this work, three different EIS capacitors are fabricated for verification, which are , , and structures. Their correspondent linear sensing range and sensitivity are pH 6–10 and 29.9 mV/pH, pH 4–8 and 52.9 mV/pH, and pH 2–8 and 57.9 mV/pH, respectively. Different post oxide annealing (POA) treatments are also carried out. The correspondent trilayer EIS devices’ sensing ranges are then modified effectively from a grown pH 2–8 to POA-treated pH 8–12 with a sensitivity of 57.4 mV/pH.

Ascorbid Acid Supplementation Reduces Severity of Exercise-Induced Asthma

PURPOSE: Ascorbic acid (vitamin C) is a major antioxidant in the airways. Data on the effect of antioxidants on exercise-induced asthma (EIA) is equivocal. Therefore, the aim of this study was to determine the effects of ascorbic acid (vitamin C) supplementation on the severity of EIA. METHODS: Eight subjects with EIA participated in a randomized, placebo controlled double-blind cross-over trial. Subjects entered the study on their normal diet and were then placed on either 2 weeks of ascorbic acid supplementation (1500mg/day) or placebo, followed by a 1 week washout period, before crossing over to the alternative diet. Pre- and post-exercise pulmonary function was assessed at the conclusion of each treatment period. In addition, urine samples were collected pre- and post-exercise and assayed for the presence of pro inflammatory mediators, cysteinyl leukotrienes (LT) C4-E4 and 9α, 11β- prostaglandin (PG) F2 which have been implicated in the pathogenesis of EIA. Urine was assayed for hydrogen peroxide (H2O2), as a marker of oxidative stress. Diet was monitored through 24-hour dietary recall to ensure that diet was not significantly different between the trials. Pre- and post exhaled breath nitric oxide (FENO) was measured as a noninvasive indicator of airway inflammation. RESULTS: Ascorbic acid supplementation significantly reduced (p <0.05) the mean maximum fall in post-exercise FEV1 (−6.4 ± 2.4%) compared to normal diet (−14.3 ± 1.6%) and placebo (−12.9 ± 2.4%). Post-exercise FENO was reduced on ascorbic acid supplementation (23.8 ± 7.7 ppb) as compared to normal diet (48.4 ±16.3 ppb) and placebo (34.1 ± 7.8 ppb). Ascorbic acid supplementation induced significant reductions (p <0.05) in urinary LTC4-E4 on the ascorbic acid supplementation (5.3 ±1.7 ng/mmol of creatinine) compared to the normal diet (15.0 ±4.0 ng/mmol/creatinine) and placebo (11.1 ±3.1 ng/mmol/creatinine). Similarly, urinary 9α, 11β-PGF was significantly reduced on the ascorbic acid supplementation (8.5 ±1.7 ng/mmol/creatinine) compared to the normal diet (20.0 ±4.5 ng/mmol/creatinine) and placebo (13.0 ± 1.8 ng/mmol). Furthermore, significant reductions (p <0.05) in urinary HO were observed on the ascorbic acid supplementation (5.6 ± 1.3 mmol/L) compared to placebo (23.6 ±5.1 mmol/L) and normal diet (12.6 ±2.9 mmol/L). CONCLUSION: These data indicate that high dose ascorbic acid supplementation reduces the severity of EIA. This reduction in the severity of EIA may occur through a mechanism by which ascorbic acid reduces reactive oxygen species, thereby leading to a reduction in bronchoconstrictive mediators.

Utilizing On-Chip Testing and Electron Microscopy to Study Fatigue and Wear in Polysilicon Structural Films

AbstractWear and fatigue are important factors in determining the reliability of microelectromechanical systems (MEMS). While the reliability of MEMS has received extensive attention, the physical mechanisms responsible for these failure modes have yet to be conclusively determined. In our work, we use a combination of on-chip testing methodologies and electron microscopy observations to investigate these mechanisms. Our previous studies have shown that fatigue in polysilicon structural thin films is a result of a ‘reaction-layer’ process, whereby high stresses induce a room-temperature mechanical thickening of the native oxide at the root of a notched cantilever beam, which subsequently undergoes moisture-assisted cracking. Devices from a more recent fabrication run are fatigued in ambient air to show that the post-release oxide layer thicknesses that were observed in our earlier experiments were not an artifact of that particular batch of polysilicon. New in vacuo data show that these silicon films do not display fatigue behavior when the post release oxide is prevented from growing, because of the absence of oxygen. Additionally, we are using polysilicon MEMS side-wall friction test specimens to study active mechanisms in sliding wear at the microscale. In particular, we have developed in vacuo and in situ experiments in the scanning electron microscope, with the objective of eventually determining the mechanisms causing both wear development and debris generation.

Three-Dimensional Array of Highly Oriented Crystalline ZnO Microtubes

The ability to generate homogeneous particulate thin films of highly oriented and highly porous microparticles of a post transition metal oxide onto polycrystalline and single-crystalline substrates, at low cost, by a template-free, aqueous low-temperature coating process is demonstrated by the fabrication of a large three-dimensional array of perpendicularly oriented hexagonal microtubes of crystalline zincite ZnO from an aqueous solution of zinc nitrate and methenamine.

New Insight into the Degradation Mechanism of Nitride Spacer with Different Post-Oxide in Submicron LDD n-MOSFET's

In this paper, the hot carrier degradation mechanisms in lightly-doped drain (LDD) n-MOS devices with silicon nitride spacer have been investigated. A low temperature chemical vapor deposited (CVD) SiO2 oxide is used as a post-oxide between source/drain surface and the nitride spacer. The gated-diode measurement in combination with the gate-induced drain leakage (GIDL) current measurement techniques have been used to analyze the stress-induced interface state and oxide charges. For the first time, it was found that the oxide charge but not the interface state generation in the post oxide will dominate the device drain current degradation. Moreover, the CVD post oxide with N2 annealing has been proposed which is able to effectively suppress the generation of oxide charges and significantly improve the device hot carrier reliability. The scaling of gate oxide thickness and the optimization of source/drain junction to improve the device reliability are also demonstrated.

5547651 Process for production and use of deactivated gaseous atomic nitrogen for post combustion gas nitric oxide emissions control : Rolfe Richard Dana Point, CA, United States assigned to Bleiweis So

5547651 Process for production and use of deactivated gaseous atomic nitrogen for post combustion gas nitric oxide emissions control : Rolfe Richard Dana Point, CA, United States assigned to Bleiweis So

The anomalous threshold voltage shift of N- and P-MOSFET under flow and reflow of BPSG film with RTA and/or furnace

Different post oxide annealing technologies, i.e. furnace and/or RTA were done in borophosphosilicate glass (BPSG) films under flow and reflow. It is found that the threshold voltage shift is apparent in P-MOSFET but small in N-MOSFET for a device with RTA reflow. Base on the charge pumping measurement, the donor-type interface states generated by RTA reflow process are supposed to play a major role in this shift. The authors explain the mechanism of RTA induced donor-like interface states in detail.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>