Vacuum emission of hot electrons from insulating and semiconducting films

Abstract

Monte Carlo calculations and vacuum emission experiments have been shown to be powerful tools to investigate the high field electronic transport in metal–insulator–semiconductor and metal–semiconductor–insulator–semiconductor layer devices. Direct proof of hot-electron acceleration in semiconducting ZnS:Mn electroluminescent layers by means of vacuum emission and energy analysis in a spherical grid analyzer has been given as it was earlier for insulating a layer of SiO2. The energy distributions show strong peaking in the low-energy region around 3 eV as well as a high-energy tail exceeding even 20 eV. The enhanced emission of low-energy electrons with increasing field F indicates impact valence band excitation and direct avalanching in thin insulating and semiconducting films of sufficient thickness, than it has been predicted by strong acoustic phonon coupling and intervalley scattering.