Holmium-related luminescence in crystalline silicon

The influence of annealing temperature of Si:Ho:O structures prepared by solid phase epitaxial technique on the photoluminescence spectra at 4.2 K was studied. The ions of Ho at 1 MeV energy and 1×1014 cm−2 dose and O at 0.14 MeV and 1×1015 cm−2 were implanted in p-Cz-Si. A fine structure of Ho-related light-emitting centers was measured with a resolution of up to 1 cm−1 in the range 3000–12 000 cm−1. A variation of Ho-related luminescence intensity in dependence on the annealing temperature is due to the transformation of the centers. Several Ho-related centers with sharp and wide lines are observed. We believe that the Ho3+ ions in the centers with the sharp and wide lines have a different surrounding — oxygen atom(s) and glass-like shell in their neighborhood, respectively.