Efficient Auger-excitation of erbium electroluminescence in reversely-biased silicon structures

In p-n junctions based on c-Si:Er, we have observed strongly efficient excitation of erbium electroluminescence at 1.54 mu m. Excitation of erbium ions is accompanied by strong recombination of free carriers indicating a participation of an Auger mechanism. A possible excitation mechanism is proposed which is the Auger recombination of electrons occupying the upper subband of the conduction band with free holes in the valence band, whereas the energy of the recombination process is transferred by Coulomb interaction to 4f electrons of an erbium ion transmitting it to the second excited state I-4(11/2) (excitation energy 1.26 eV). The observed three-level excitation of erbium ions is promising for the development of a Si:Er laser. (C) 1999 American Institute of Physics. [S0003-6951(99)04343-0].