A graphene-oxide-semiconductor (GOS) planar-type electron source was fabricated by direct synthesis of graphene on an oxide layer via low-pressure chemical vapor deposition. It achieved a maximum electron emission efficiency of 32.1% by suppressing the electron inelastic scattering within the topmost gate electrode using graphene electrode. In addition, a 100-mA/cm 2 electron emission current density was observed at 16.2-% electron emission efficiency. The electron energy spread was well fitted to Maxwell-Boltzmann distribution, which indicates that the emitted electrons are thermally equilibrium state within the electron source. The full-width at half-maximum energy spread of the emitted electrons was approximately 1.1 eV. The electron emission efficiency did not deteriorate after more
Photonic structures created by coupling a narrow resonance to a broad resonance can significantly improve the sensitivity of optical sensors. We investigated a planar metal-insulator-metal (MIM) multilayered structure using attenuated total reflection to couple surface plasmon polaritons with the waveguide (WG) mode. A plasmon-induced transparency (PIT) to plasmon-induced adsorption (PIA) transformation was realized by controlling the coupling strength between the incident light and the WG mode. The results indicated that PIT and PIA have differing coupling strength and reflectance phase at surface plasmon resonance. Moreover, Fano resonance was realized by adjusting the center of the absorption band of the WG mode.
An effective mean-free path of hot electrons in the conduction band of SiO2 in a Si-gate metal–oxide–semiconductor (MOS) electron tunneling cathode was measured and found to be about 0.7 nm. Following these observations, we proposed and fabricated a depletion gate MOS electron tunneling cathode. The highest transfer ratio of 13.3% was achieved in the cathode at the low emission current level, which was considerably higher than that of tunneling cathodes studied in the past. However, the ratio decreased drastically at high current due to the hole injection into the depletion region from the gate.
Resonance frequency shift of a zinc oxide-(ZnO-) functionalized microcantilever as a response to carbon monoxide (CO) gas has been investigated. Here, ZnO microrods were grown on the microcantilever surface by a hydrothermal method. The measurement of resonance frequency of the microcantilever vibrations due to the gas was carried out in two conditions, that is, gas flow with and without air pumping into an experiment chamber. The results show that the resonance frequency of the ZnO-functionalized microcantilever decreases because of CO in air pumping condition, while it increases when CO is introduced without air pumping. Such change in the resonance frequency is influenced by water vapor condition, and a possible model based on water-CO combination was proposed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.