Effective Auger excitation of erbium luminescence by hot electrons in silicon

In an electroluminescent structure based on erbium-doped crystalline silicon we have found and studied a new mechanism of excitation of erbium ions involving Auger recombination of electrons from the upper subband of the conduction band with holes from the valence band. The new excitation mechanism is weak at low temperatures, but it is resonantly enhanced at 160 K, when the energy distance of the edge of the upper subband of the conduction band from the valence band edge coincides with the energy of the second excited state of the erbium ion due to temperature shrinking of the silicon energy gap. (C) 1999 Elsevier Science B.V. All rights reserved,