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Summary form only given. In this talk, we would like to present the applications of graphene-based materials on large-area photovoltaic and optoelectronic devices. Chemically derived graphene-oxide (GO) from solution processes or epitaxial graphene obtained from chemical vapor deposition (CVD) have been demonstrated to replace the ITO electrode. GO could be also a simple solution processable alternative...
Field emission electron sources are an excellent alternative for a myriad of applications such as flat panel displays, microwave tubes and plasma thrusters requiring highly efficient and compact electron sources with a short turn-on time, high power efficiency, and low thermal signature, Although field emission array (FEA) devices with several different triode configurations have been developed, there...
With the limitation of epitaxial growth technique, the approximately exponential-doping structure is actually a special kind of gradient-doped structure, in which the doping concentration in the active-layer of the III-V photocathode varies exponentially from bulk to surface. This doping structure can result in a linearly downward band structure which helps form a constant built-in electric fields...
A study of the field emission properties of ZrO2/W and ZrO2/Mo nanoheterostructures is presented. The nanoheterostructure (NHS) was represented by a thin (~3-10 nm) ZrO2 layer at the tip of a needle-shaped W<;100>, W<;111>, Mo<;100> and Mo<;111> microcrystals (MC). It is established, that at temperature (Ts) of NHS substance Ts~ (1900±100) K process of thermal field electron...
Summary form only given. Graphene has a one-dimensional edge of atomic thickness, excellent electrical conductivity, and good mechanical properties, which qualify it as an attractive novel field emission emitter. Several groups had demonstrated that graphene does show promising electron emission properties, such as low emission threshold field and large emission current density[1-7]. The traditional...
Summary form only given. We present a simple technology for the fabrication of CNTs films cathode by utilizing method of rubbing CNT powders onto the polished substrates. The metallic substrates were polished by 10000 mesh white fused alumina powder at first. Then, the CNTs were rubbed on them. After that process, the metallic substrates were covered by CNTs films uniformly and firmly, as characterized...
In this study, the FE current is measured pixel-by-pixel by setting the bias voltage at a value much larger than the tip work function after temporarily opening the feedback loop for the constant current (CC) operation of STM, where the electrons tunnel through a triangle potential barrier, as shown in Figs. 1 (a) and (b). Figs. 2 (a) and (b) show the STM and FE images simultaneously obtained from...
Summary form only given. The paper that we are going to present is about the characterization of field emission of a non-uniform distribution of emitters in a sphere-plane diode. In a recent article we showed that field emission in a non-uniform field can give information about the nonuniform distribution of emitters [1]. It can also explain the apparent non reproducibility of flat samples, which...
It is of special interest to obtain a single nanodimensional emitting protrusion on the surface of a tungsten carbide emitter, which would serve as an ideal point source of electrons and ions. However, it is difficult to grow a single nanodimensional protrusion on the surface of a tungsten carbide emitter. In this study, the task was solved as follows. In the course of a field crystal growth, each...
The electrical conductivity of many TCNQ charge-transfer complexes generated much interest in the subject of field emission displays (FEDs). Ag-TCNQ nanowires were prepared using a vacuum vapor-transport reaction method at a lower temperature, showing good field emission properties in our previous work. In this work, XPS test was carried out using the VG Scienctific suface analysis instrument (XR5...
In this work were investigated on field-emission properties of the so-called quantum dots. Field emission is an emission of electrons induced by external electromagnetic fields. This is the only form of emission, which does not require the preliminary electron excitation. Before the experiment the surface of the sample was processed in several stages. Sample was placed into the vacuum system and connected...
The electron emission properties from carbon nanocomposite films deposited at elevated temperatures using pulsed laser deposition techniques have been studied. By using both Fowler-Nordhiem and Wentzel-Kramers-Brillouin approximation for electron tunneling, changes of the internal enhancement factors were studied. The internal enhancement ratios were found to have a ratio of β100: β400: β700 = 1 :...
In this paper, the structures and field emission properties of energetic C ion irradiated SiNWs have been investigated and influence of ion irradiation on structures and properties has been discussed. Vertically SiNW arrays are synthesized by using Ag-assisted electroless-chemical etching at room temperature, as reported in literatures. The process mainly comprises three steps: 1) surface cleaning...
Summary form only given. Silicon carbide nanowires with junctions are considered to be of potential value in nanoelectronics. A simple method by catalyst-assisted vapor-liquid-solid reaction for producting Y-junction silicon carbide nanowires is described. The Y-junction silicon carbide nanowires are investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It...
Free Electron Lasers (FELs) make significant demands on the photocathode / drive laser used to generate electron bunches, but no photocathode source simultaneously satisfies needed demands of lifetime, quantum efficiency, and response. High gain mm-wave (and beyond) amplifiers make analogous demands. A diamond current amplifier may enable progress by exploiting the high yield associated with secondary...
Summary form only given. Commercial expandable graphite was heat at 900 °C to get the worm-like graphene nanosheets. Using sulfuric acid and potassium permanganate to oxidize the expanded graphene nanosheet could further minish the thickness of graphene oxide sheet to less than 1nm, and this way to get the graphene was proved to be mass producible (tens of gram). Free-standing graphene oxide paper...
In this paper, ZnO nanomaterials with high effective specific surface area have been prepared and subsequently deposited on the SAW transducer as sensitive layer, finally the responses of the sensor to different ethanol gas concentrations were investigated at room temperature.
The GaN sample doped with Mg at a level of 1.6x41017 cm-3 were grown through MOCVD on a sapphire substrate, The thick is 150nm, a buffer layer of AlN of 20 nm is grown. The opaque GaN sample is cleaned with physical and chemical treatment to remove large amount of contaminations The subsequent heating process of 710°C in the high-vacuum chamber makes the surface with the lowest content of oxygen and...
Summary form only given. Ballistic n-type carbon nanotube (CNT) based field-effect transistors (FETs) have been fabricated by contacting semiconducting single wall CNTs using Sc. Together with the demonstrated ballistic p-type CNT FETs using Pd contacts, this closes the gap for doping free fabrication of CNT based ballistic CMOS and high performance optoelectronic devices. The feasibility of this...
In this paper the effect of single nanosecond laser pulse irradiation on the microstructure and field emission (FE) properties of carbon films is studied. Amorphous carbon films are exposed to a single pulse of a 248 nm excimer laser with pulse width of 23 nsec and varying energies. Microstructural changes of the films are investigated by Raman spectroscopy, transmission electron microscopy and electron...
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