Sharp-line, donor–acceptor pair recombination luminescence in Si(In,Li), Si(Ga,Li), Si(Al,Li), and Si(B,Li)

The observation of sharp-line, donor–acceptor pair recombination luminescence in Si following the diffusion of the donor Li into samples previously doped with the acceptors B, Al, Ga, or In is reported. Shell assignments have been made for most of the numerous new photoluminescence lines. These assignments indicate that the principal donor introduced into the samples was the Li–O complex, and that the principal acceptor in the In-doped samples was the In–X centre. Results for the Al- and Ga-doped samples are consistent with ordinary Al and Ga acceptors, while those for B are inconclusive due to the extreme weakness of the sharp-line structure. This study not only confirms that donor–acceptor pair recombination in Si can give rise to sharp luminescence line series, but shows that this process is quite widespread, given the proper concentrations of donors and acceptors.