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

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.