scholarly journals Ultraviolet Photodetection Based on High-Performance Co-Plus-Ni Doped ZnO Nanorods Grown by Hydrothermal Method on Transparent Plastic Substrate

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1225 ◽  
Author(s):  
Hafiz Muhammad Salman Ajmal ◽  
Fasihullah Khan ◽  
Kiyun Nam ◽  
Hae Young Kim ◽  
Sam Dong Kim
Keyword(s):  
Hydrothermal Method ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Spectral Response ◽  
Zno Nanorods ◽  
Ultra Violet ◽  
Plastic Substrate ◽  
Processing Temperature ◽  
Electrode Structure ◽  
Transparent Plastic

A growth scheme at a low processing temperature for high crystalline-quality of ZnO nanostructures can be a prime stepping stone for the future of various optoelectronic devices manufactured on transparent plastic substrates. In this study, ZnO nanorods (NRs) grown by the hydrothermal method at 150 °C through doping of transition metals (TMs), such as Co, Ni, or Co-plus-Ni, on polyethylene terephthalate substrates were investigated by various surface analysis methods. The TM dopants in ZnO NRs suppressed the density of various native defect-states as revealed by our photoluminescence and X-ray photoelectron spectroscopy analysis. Further investigation also showed the doping into ZnO NRs brought about a clear improvement in carrier mobility from 0.81 to 3.95 cm2/V-s as well as significant recovery in stoichiometric contents of oxygen. Ultra-violet photodetectors fabricated with Co-plus-Ni codoped NRs grown on an interdigitated electrode structure exhibited a high spectral response of ~137 A/W, on/off current ratio of ~135, and an improvement in transient response speed with rise-up and fall-down times of ~2.2 and ~3.1 s, respectively.

scholarly journals High-Performance Flexible Ultraviolet Photodetectors with Ni/Cu-Codoped ZnO Nanorods Grown on PET Substrates

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1067 ◽  
Author(s):  
Hafiz Muhammad Salman Ajmal ◽  
Fasihullah Khan ◽  
Noor Ul Huda ◽  
Sunjung Lee ◽  
Kiyun Nam ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Electronic Device ◽  
Deep Level ◽  
Zno Nanorods ◽  
Ultra Violet ◽  
Device Fabrication ◽  
Electrode Structure ◽  
Large Area ◽  
X Ray

As a developing technology for flexible electronic device fabrication, ultra-violet (UV) photodetectors (PDs) based on a ZnO nanostructure are an effective approach for large-area integration of sensors on nonconventional substrates, such as plastic or paper. However, photoconductive ZnO nanorods grown on flexible substrates have slow responses or recovery as well as low spectral responsivity R because of the native defects and inferior crystallinity of hydrothermally grown ZnO nanorods at low temperatures. In this study, ZnO nanorod crystallites are doped with Cu or Ni/Cu when grown on polyethylene terephthalate (PET) substrates in an attempt to improve the performance of flexible PDs. The doping with Ni/Cu or Cu not only improves the crystalline quality but also significantly suppresses the density of deep-level emission defects in as-grown ZnO nanorods, as demonstrated by X-ray diffraction and photoluminescence. Furthermore, the X-ray photoelectron spectroscopy analysis shows that doping with the transition metals significantly increases the oxygen bonding with metal ions with enhanced O/Zn stoichiometry in as-grown nanorods. The fabricated flexible PD devices based on an interdigitated electrode structure demonstrates a very high R of ~123 A/W, a high on-off current ratio of ~130, and a significant improvement in transient response speed exhibiting rise and fall time of ~8 and ~3 s, respectively, by using the ZnO nanorods codoped by Ni/Cu.

ZnO Nanorods Based Ammonia Gas Sensors with Interdigitized Electrodes

2011 ◽  
Vol 694 ◽  
pp. 155-159
Author(s):  
Tai You Chen ◽  
Jian Sheng Wu ◽  
Chi Shiang Hsu ◽  
Po Cheng Chou ◽  
Huey Ing Chen ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Gas Sensors ◽  
High Performance ◽  
Zno Nanorods ◽  
Sensor Response ◽  
Electrode Spacing ◽  
Ammonia Gas ◽  
Ammonia Sensing ◽  
Sensing Applications ◽  
Ammonia Gas Sensors

The ZnO nanorods-based ammonia (NH3) gas sensors with different electrode spacing are fabricated and studied. Experimentally, the hexagonal ZnO nanorods were prepared by a hydrothermal method. The diameter and length of ZnO nanorods were about 179±2, 1806±5 nm, respectively. By shrinking the electrode spacing, the sensor response of studied device is improved and the sensor response is enhanced more than ten times in magnitude. The improved NH3 sensing ability caused by shrink electrode spacing is attributed to the presence of more grain boundaries and depletion layers. Therefore, the studied device with the shrink of electrode spacing provides a promise for high-performance ammonia sensing applications.

scholarly journals Synthesis of Fe-Doped ZnO Nanorods by Rapid Mixing Hydrothermal Method and Its Application for High Performance UV Photodetector

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Chan Oeurn Chey ◽  
Ansar Masood ◽  
A. Riazanova ◽  
Xianjie Liu ◽  
K. V. Rao ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Zno Nanorods ◽  
Hexagonal Wurtzite Structure ◽  
Secondary Phases ◽  
Simple Method ◽  
Uv Photodetector ◽  
X Ray ◽  
Doped Zno ◽  
Schottky Devices

We have successfully synthesized Fe-doped ZnO nanorods by a new and simple method in which the adopted approach is by using ammonia as a continuous source ofOH-for hydrolysis instead of hexamethylenetetramine (HMT). The energy dispersive X-ray (EDX) spectra revealed that the Fe peaks were presented in the grown Fe-doped ZnO nanorods samples and the X-ray photoelectron spectroscopy (XPS) results suggested that Fe3+is incorporated into the ZnO lattice. Structural characterization indicated that the Fe-doped ZnO nanorods grow along thec-axis with a hexagonal wurtzite structure and have single crystalline nature without any secondary phases or clusters of FeO or Fe3O4observed in the samples. The Fe-doped ZnO nanorods showed room temperature (300 K) ferromagnetic magnetization versus field (M-H) hysteresis and the magnetization increases from 2.5 μemu to 9.1 μemu for Zn0.99Fe0.01O and Zn0.95Fe0.05O, respectively. Moreover, the fabricated Au/Fe-doped ZnO Schottky diode based UV photodetector achieved 2.33 A/W of responsivity and 5 s of time response. Compared to other Au/ZnO nanorods Schottky devices, the presented responsivity is an improvement by a factor of 3.9.

scholarly journals Novel Carbon Dots Derived from Glycyrrhizae Radix et Rhizoma and Their Anti-Gastric Ulcer Effect

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1512
Author(s):  
Yuhan Liu ◽  
Meiling Zhang ◽  
Jinjun Cheng ◽  
Yue Zhang ◽  
Hui Kong ◽  
...  
Keyword(s):  
Gastric Ulcer ◽  
Photoelectron Spectroscopy ◽  
Carbon Dots ◽  
High Performance ◽  
Raw264.7 Cells ◽  
Mice Model ◽  
X Ray ◽  
Glycyrrhizae Radix ◽  
Transmission Electron ◽  
High Resolution Tem

Glycyrrhizae Radix et Rhizoma (GRR) is one of the commonly used traditional Chinese medicines in clinical practice, which has been applied to treat digestive system diseases for hundreds of years. GRR is preferred for anti-gastric ulcer, however, the main active compounds are still unknown. In this study, GRR was used as precursor to synthesize carbon dots (CDs) by a environment-friendly one-step pyrolysis process. GRR-CDs were characterized by using transmission electron microscopy, high-resolution TEM, fourier transform infrared, ultraviolet-visible and fluorescence spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction and high-performance liquid chromatography. In addition, cellular toxicity of GRR-CDs was studied by using CCK-8 in RAW264.7 cells, and the anti-gastric ulcer activity was evaluated and confirmed using mice model of acute alcoholic gastric ulcer. The experiment confirmed that GRR-CDs were the spherical structure with a large number of active groups on the surface and their particle size ranged from 2 to 10 nm. GRR-CDs had no toxicity to RAW264.7 cells at concentration of 19.5 to 5000 μg/mL and could reduce the oxidative damage of gastric mucosa and tissues caused by alcohol, as demonstrated by restoring expression of malondialdehyde, superoxide dismutase and nitric oxide in serum and tissue of mice. The results indicated the explicit anti-ulcer activity of GRR-CDs, which provided a new insights for the research on effective material basis of GRR.

scholarly journals Elucidation of the Crystal Growth Characteristics of SnO2 Nanoaggregates Formed by Sequential Low-Temperature Sol-Gel Reaction and Freeze Drying

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1738
Author(s):  
Saeid Vafaei ◽  
Alexander Wolosz ◽  
Catlin Ethridge ◽  
Udo Schnupf ◽  
Nagisa Hattori ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Low Temperature ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Freeze Drying ◽  
Sno2 Nanoparticles ◽  
Sol Gel ◽  
Functional Materials ◽  
Cost Effective ◽  
High Concentration

SnO2 nanoparticles are regarded as attractive, functional materials because of their versatile applications. SnO2 nanoaggregates with single-nanometer-scale lumpy surfaces provide opportunities to enhance hetero-material interfacial areas, leading to the performance improvement of materials and devices. For the first time, we demonstrate that SnO2 nanoaggregates with oxygen vacancies can be produced by a simple, low-temperature sol-gel approach combined with freeze-drying. We characterize the initiation of the low-temperature crystal growth of the obtained SnO2 nanoaggregates using high-resolution transmission electron microscopy (HRTEM). The results indicate that Sn (II) hydroxide precursors are converted into submicrometer-scale nanoaggregates consisting of uniform SnO2 spherical nanocrystals (2~5 nm in size). As the sol-gel reaction time increases, further crystallization is observed through the neighboring particles in a confined part of the aggregates, while the specific surface areas of the SnO2 samples increase concomitantly. In addition, X-ray photoelectron spectroscopy (XPS) measurements suggest that Sn (II) ions exist in the SnO2 samples when the reactions are stopped after a short time or when a relatively high concentration of Sn (II) is involved in the corresponding sol-gel reactions. Understanding this low-temperature growth of 3D SnO2 will provide new avenues for developing and producing high-performance, photofunctional nanomaterials via a cost-effective and scalable method.

Synergistic effect of carbon nanotubes and graphitic carbon nitride on the enhanced supercapacitor performance of cobalt diselenide-based composites

2021 ◽  
Author(s):  
Mingjie Li ◽  
Xuan Zheng ◽  
Xiang Li ◽  
Youjun Yu ◽  
Jinlong Jiang
Keyword(s):  
Carbon Nanotubes ◽  
Transition Metal ◽  
Synergistic Effect ◽  
Hydrothermal Method ◽  
High Performance ◽  
Carbon Nitride ◽  
Electrode Materials ◽  
One Dimensional ◽  
Supercapacitor Performance ◽  
Metal Selenides

Recently, transition metal selenides have been investigated extensively as promising electrode materials for high-performance supercapacitors. Herein, the multi-component CoSe2/CNTs@g-C3N4 composites are prepared using a two-step hydrothermal method by incorporating one-dimensional...

scholarly journals High-Performance Resistive Switching in Solution-Derived IGZO:N Memristors by Microwave-Assisted Nitridation

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1081
Author(s):  
Shin-Yi Min ◽  
Won-Ju Cho
Keyword(s):  
Resistive Switching ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Electric Pulse ◽  
Chemical Species ◽  
Optical Absorption Coefficient ◽  
Microwave Assisted ◽  
Synthesis Strategy ◽  
Metal Insulator Metal ◽  
Switching Characteristics

In this study, we implemented a high-performance two-terminal memristor device with a metal/insulator/metal (MIM) structure using a solution-derived In-Ga-Zn-Oxide (IGZO)-based nanocomposite as a resistive switching (RS) layer. In order to secure stable memristive switching characteristics, IGZO:N nanocomposites were synthesized through the microwave-assisted nitridation of solution-derived IGZO thin films, and the resulting improvement in synaptic characteristics was systematically evaluated. The microwave-assisted nitridation of solution-derived IGZO films was clearly demonstrated by chemical etching, optical absorption coefficient analysis, and X-ray photoelectron spectroscopy. Two types of memristor devices were prepared using an IGZO or an IGZO:N nanocomposite film as an RS layer. As a result, the IGZO:N memristors showed excellent endurance and resistance distribution in the 103 repeated cycling tests, while the IGZO memristors showed poor characteristics. Furthermore, in terms of electrical synaptic operation, the IGZO:N memristors possessed a highly stable nonvolatile multi-level resistance controllability and yielded better electric pulse-induced conductance modulation in 5 × 102 stimulation pulses. These findings demonstrate that the microwave annealing process is an effective synthesis strategy for the incorporation of chemical species into the nanocomposite framework, and that the microwave-assisted nitridation improves the memristive switching characteristics in the oxide-based RS layer.

scholarly journals Novel core–shell structured Si/S-doped-carbon composite with buffering voids as high performance anode for Li-ion batteries

RSC Advances ◽  
2017 ◽  
Vol 7 (5) ◽  
pp. 2407-2414 ◽  
Author(s):  
Dan Shao ◽  
Inna Smolianova ◽  
Daoping Tang ◽  
Lingzhi Zhang
Keyword(s):  
Hydrothermal Method ◽  
High Performance ◽  
Reversible Capacity ◽  
Carbon Composite ◽  
Core Shell ◽  
Li Ion Batteries ◽  
Li Ion

Novel core–shell structured Si/S-doped carbon composite with buffering voids prepared by hydrothermal method and followed by carbonization and removal of template layer, exhibiting a reversible capacity of 664 mA h g−1 over 300 cycles.

High Performance Magneto-Optical Disk Using A New Plastic Substrate

1988 ◽  
Author(s):  
Toshio Niihara ◽  
Shinkichi Horigome ◽  
Ryoichi Sudou ◽  
Hiroyuki Suzuki ◽  
Masafumi Yoshihiro ◽  
...  
Keyword(s):  
High Performance ◽  
Optical Disk ◽  
Plastic Substrate
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