New efficient mechanism of excitation of electroluminescence from erbium ions in crystalline silicon

In p-n junctions based on c-Si : Er we have realized highly efficient excit ation of erbium electroluminescence at 1.54 mu m with an efficiency close t o unity. A possible mechanism is Anger recombination of electrons occupying the upper subband of the conduction band with free holes in the valence ba nd whereas the energy of the recombination process is transferred by Coulom b interaction to 4f-electrons of an erbium ion transmitting it to the secon d excited state I-4(11/2) (excitation energy 1.26 eV). The observed three-l evel excitation of erbium ions is promising for development of a Si:Er lase r. (C) 1999 Elsevier Science B.V. All rights reserved.