Cathodoluminescence was used to investigate the phenomenon of relatively efficient band-to-band luminescence from Si specimens processed to contain near surface dislocations. Dislocations were produced either by ion implantation and subsequent high-temperature annealing or by mechanical abrasion of specimens having a wide range of doping concentrations. It was found that the luminescence was not directly related to the presence of dislocations and, in some cases, could be enhanced by low temperature annealing. This luminescence behaviour was explained by the effect of competing non-radiative recombination due to impurity deep levels and Auger recombination. The enhancement observed in some specimens was due to gettering of the deep level impurities.

The Role of Dislocations in Producing Efficient Near-Bandgap Luminescence from Silicon. K.Fraser, D.Stowe, S.Galloway, S.Senkader, R.Falster, P.Wilshaw: Physica Status Solidi C, 2007, 4[8], 2977-80