| abstract |
The emitter 100 has an electron supply layer 10 and a tunneling layer 20 formed on the electron supply layer. Optionally, an insulator layer 78 is formed on the electron supply layer and has a defined opening in which the tunneling layer is formed. A cathode layer 14 is formed on the tunneling layer. A conductive layer 82 is partially disposed on the cathode layer and, if present, is partially disposed on the insulator layer. The conductive layer defines an opening, providing a surface for energy radiation 22 of electrons 16 and / or photons 18. Preferably, but optional, as the emitter undergoes an annealing process, the supply of electrons tunneled from the electron supply layer to the cathode layer is increased. |