Influence of the orientation of the silicon substrate on the properties ofavalanche Si : Er : O light-emitting structures

The influence of the orientation of silicon on the structural and luminesce nce properties of avalanche light-emitting diodes fabricated by the coimpla ntation of erbium and oxygen followed by solid-phase epitaxial (SPE) crysta llization of the amorphized layer is considered. The luminescence propertie s are a consequence of the formation of various structural defects during t he SPE crystallization: V-shaped dislocations and erbium precipitates form in (100) Si:Er:O layers, and larger structural defects, i.e, twins, are obs erved in (111) Si:Er:O layers along with an increase in the dislocation den sity by more than four orders of magnitude in comparison with the (100) ori entation. The luminescence properties of avalanche and tunnel light-emittin g diodes are also compared. In contrast to tunnel diodes, in avalanche diod es erbium ions are excited in the entire space-charge layer, and the effect ive excitation cross section of the Er3+ ions and their lifetime in the exc ited state are 3-4 times larger. (C) 1999 American Institute of Physics. [S 1063-7826(99)00706-1].