  We have fabricated light emitting diodes (LEDs) with Schottky contacts on
Si-nanocrystals formed by simple techniques as used for standard Si devices.
Orange electroluminescence (EL) from these LEDs could be seen with the naked
eye at room temperature when a reverse bias voltage was applied. The EL
spectrum has a major peak with a photon energy of 1.9 eV and a minor peak with
a photon energy of 2.2 eV. Since the electrons and holes are injected into the
radiative recombination centers related to nanocrystals through avalanche
breakdown, the voltage needed for a visible light emission is reduced to 4.0 -
4.5 V, which is low enough to be applied by a standard Si transistor.
