Synthesis and characteristics of carbon nanotube using plasma arc discharge

Carbon nanoparticles (CNP) were synthesized in arc plasma discharge using a simple, low-cost and toxic-free precursor gas. The structural and electrical characteristics were examined. SEM image showed existence of a high density and uniform nanostructures within the cylindrical bulk CNP tube. The tube diameter and its length was 28.5 μm and 316.7 μm, respectively. The average diameter of the nanoparticles grown in the tube was 600 nm. The electrical characteristics revealed low resistance with R = 7.23 kΩ with Cu electrodes. In addition, the device exhibited a high conductivity of 3.6 x 107 Scm-1. These results indicate the potential of CNP material for power device applications

3D simulation investigating ZnO NWFET characteristics

3D Simulation was carried out and compared with fabricated ZnO NWFET. The device had the following electrical output characteristics: mobility value of 10.0 cm2 /Vs at a drain voltage of 1.0 V, threshold voltage of 24 V, and subthreshold slope (SS) of 1500 mV/decade. The simulation showed that the device output results are influenced by two main issues: (i) contact resistance (Rcon ≈ 11.3 MΩ) and (ii) interface state trapped charge number density (QIT = 3.79 x 1015 cm-2). The QIT was derived from the Gaussian distribution that depends on two parameters added together. These parameters are: an acceptor-like exponential band tail function gGA(E) and an acceptor-like Gaussian deep state function gTA(E). By de-embedding the contact resistance, the simulation is able to improve the device by producing excellent field effect mobility of 126.9 cm2 /Vs

Review—Three dimensional zinc oxide nanostructures as an active site platform for biosensor: Recent trend in healthcare diagnosis

Morphology effect is one of the essential factors that influence the performance of electrochemical biosensors based on ZnO nanostructures. These nanostructures are characterized by anisotropic growth with different dimensionalities such as zerodimensional, one-dimensional, and two-dimensional. More interestingly, when combining each dimension into another advanced dimensionality, i.e. the three-dimensional (3-D), exceptional properties can be generated that are not otherwise found in low dimensionalities. The outstanding popularity of 3-D ZnO stems from many factors, with one of the most important being its synergic advantages from its low dimensional sub-unit and the additional surface area of the 3-D structure due to an increased geometric volume. This review briefly describes the principles and growth mechanism factors of 3-D ZnO via solution-based approaches and additional advanced methods. The paper further expands on the latest advancement of research into the 3-D ZnO nanostructure-based electrochemical biosensors to detect biomolecules that harm humankind. We also discussed the analytical performance of these biosensors using different nanocomposite materials. Additionally, limitations and suggestions on particular sensing works are proposed. Lastly, the five-year progress in research into 3-D ZnO-based electrochemical biosensors’ performance in healthcare diagnosis is compared and future challenges presente

Effects of Post-Deposition Annealing Temperatures on the Composition of Interfacial Layer at Germanium (Ge) /Aluminium Oxide (Al2 O3 ) (Kesan Suhu Penyepuhlindapan Pasca Pemendapan ke atas Komposisi Antara Muka Lapisan Oksida Germanium (Ge)/Aluminium (Al2 O3 ))

The understanding of chemical bonding structure of high k dielectrics/Germanium (Ge) interface is upmost importance in order to form a good quality dielectric/Ge interface in fabricating Ge metal oxide semiconductor field effect transistor (MOSFETs). In addition, there is still no detail explanation on the interfacial growth of dielectrics/Ge under the influenced of different temperature of post deposition anneal. In current work, the effects of post deposition anneal (PDA) temperature between 400°C and 600°C on the chemical composition of interfacial layer between Ge and Al2 O3 were examined by X-ray photoelectron spectroscopy (XPS). Investigation on thermal stability and structural characteristics for gate structure of Al2 O3 dielectric grown on Ge by RF sputtering was done by analyzing X-ray photoelectron spectroscopy (XPS) spectra. It is observed that the oxygen deficient region in interfacial layer (IL) is enhanced rather than fully oxidized Al2 O3 with increased PDA temperatures. These undesired phenomena caused shrinkage of IL at Ge/Al2 O3 interface at higher temperature of 600°C

ZnO thin film transistor: effect of traps and grain boundaries

Recently ZnO has drawn a lot of attention in semiconductor industry due to its interesting features. High exciton binding energy, high resistivity against radiation, high breakdown voltage, low temperature deposition are some of the interesting features of this material. Zinc oxide TFT device gains an increasing interest for its potential in sensing applications due to its biocompability, chemical stability and simple fabrication process with various methods and high surface-to-volume ratio. However, ZnO TFT devices from previous work exhibited poor ION and field effect mobility. This work investigates the cause of its poor performance by focusing only two factors: traps and defects in the channel and grain boundary. The work was performed in Silvaco TCAD 2D simulator. It was found that a single grain boundary in the channel causes a reduction of the ION by 95%. The effect in the ION is less severe when traps and defects were introduced in the ZnO channel. The results can assist in optimizing the TFT device performance for sensing applications