Atmospheric operation of original electron emission device and generation of reactive species

Abstract

We developed herein an original electron emission device that can stably operate in the atmosphere. The important features of the device are that the energy of electrons is as extremely small as several eV, the emission current in the atmosphere is as large as several μA/cm2, and the durability is of several hundred hours. These characteristics are obtained by an original device structure based on a 1 μm-thick Ag nanoparticle/polymer composite layer. The electron emission device does not require a strong electric field in the space between the emitter and the collector as required for discharge or plasma. The physical mechanism of electron emission is a mixture of field emission according to the Fowler–Nordheim plot and electron emission caused by breakdown. The energy of the emitted electrons depends on the applied voltage and can be controlled. The electrons emitted from the device can generate various ions and radicals.

Development of Ion Mobility Spectrometry with Novel Atmospheric Electron Emission Ionization for Field Detection of Gaseous and Blister Chemical Warfare Agents

“…Under AEE, low-energy electrons (with a peak around 5 eV) could be produced, , which could be detected in this experiment (Figure ). A single RIP was observed, suggesting the formation of only O 2 – .…”

“…Sharp corporation (Yamatokouriyama, Nara, Japan) recently succeeded in developing a novel electron emission device consisting of a heterogeneous semiconductor layer composed of insulating materials and conductive nanoparticles that displayed stable operation at atmospheric pressure . A feature of this device is that the energy of the emitted electrons is as small as several electron volts and can be controlled over long durations . The emitted electron manifests as a soft attachment to electron-drawing molecules such as O 2 without the formation of harmful byproducts such as O 3 .…”

A novel electron emission-based cell culture device promotes cell proliferation and differentiation of pre-osteoblastic MC3T3-E1 cells

“…O 2 - ions were detected in the region between the electrode and liquid surface (data not shown). An electron spin resonance study using the spin trap method showed the presence of HO·, H·, and O 2 -, whose concentration was approximately 2.0, 1.0, and 0.3 μM, respectively, in the liquid after 60 min electric emission with an applied voltage of about 20 V [4]. The present study was performed with 1 min electron emission, and the estimated concentrations were much lower than these values.…”

“…The electrons released into the atmosphere generate negative ions and radicals, and the negative ions move to the collector electrode along the electric field. Our previous electron spin resonance (ESR) study using spin trap reagent 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) showed that products generated from an electron emission device in the aqueous phase contained the hydroxyl radical (HO·), hydrogen radical (H·), and superoxide (O 2 - ) [4]. Hydrogen peroxide (H 2 O 2 ) was also detected, and it is considered that these reactive species are derived from O 2 and H 2 O dissociated by ionized O 2 .…”

Atypical secondary electron emission yield curves of very thin SiO2 layers: Experiments and modeling

“…[1][2][3] This physical phenomenon is largely involved in scanning electron microscopy (SEM), [4][5][6] plasma physics, 7 space applications, 8,9 particle accelerators, 10 among other fields, and lays down the principle of operation of many devices. [11][12][13][14] Given the large number of applications using electron emission for their operation, a lot of effort has been made during the last century to determine the electron emission yield from different materials, being conducting, semiconducting or insulating ones. 1,2 However, due to some peculiarities related to the nature of materials, the electron emission phenomenon from thin dielectric layers remains an open field of research.…”