A porous silicon diode as a source of low-energy free electrons at milli-Kelvin temperatures

We have developed a porous silicon (PS) diode that yields free-electron currents with energies < 0.1 eV below 77 K. The power dissipated during emission is low so that pulses of electrons can be produced below 100 mK without raising the temperature of the system. Free electrons were generated in liquid He-4 and He-3 as well. The device was developed as a source of electrons for a quantum computing system using electrons on the surface of a dielectric film. The results suggest that a Poole-Frenkel type of mechanism accounts for the observed electric-field-enhanced conduction but the electron emission mechanism is not well understood in the present models of PS. (c) 2005 American Institute of Physics.