Infrared light emission due to radiation damage in crystalline silicon

We have observed a set of broad luminescence bands between 1.07 and 0.85 eV, in He-implanted Si annealed in vacuum. These emissions are very similar to those of H-implanted and annealed Si, demonstrated by different groups in last years, in which H was believed to play a fundamental role. A comparison between the photoluminescence of He-implanted Si and of H-implanted Si, has allowed to conclude that the infrared photoluminescence of the Si:H system does not depend on H presence, but must be completely ascribed to the damage produced by the bombardment of Si with light ions. (C) 1997 Published by Elsevier Science Ltd. All rights reserved.