Surface plasmon polariton-assisted electron emission and voltage-controlled negative resistance of Al-Al_2O_3-Au diodes

摘要

Electrons are ejected from an Au surface when their energy exceeds the work function of Au, φ_(Au), which is 5.2 eV. The threshold voltage for the onset of electron emission from Al-Al_2O_3-Au diodes that develop voltage-controlled negative resistance in their current-voltage characteristics is V_(EM) ≌ 2.4 V. The threshold voltage for electroluminescence (EL) is V_(EL)= 1.6-2.0 V. The interaction of electrons with surface plasmon polaritons (SPPs) produced at the Al_2O_3-Au interface by EL photons provides a mechanism by which electrons gain enough energy to surmount the work function barrier at the Au-vacuum interface when the applied voltage is less than 5.2 V. The interaction of EL photons with surface plasmons in Au is a new mechanism for creating SPPs.