Preparation and characterization of the Si:Co layer for intermediate band solar cell applications

The Co-implanted silicon layers with rapid thermal process (RTP) have been prepared for intermediate band materials. The characterization of the Si:Co layer has been analyzed and discussed. The results show that the Co concentrations in effective implanted region of the Si layers exceed the Mott limit, satisfying the requirement for the formation of intermediate band in silicon. The Co-implanted samples are well crystallized by RTP treatment. The effective lifetime of the carriers in the samples increases with the Co dose implanted. This indicates that the non-radiative recombination has been suppressed in the post-annealed samples. Furthermore, the optical absorptance of the samples is much enhanced in the wavelength range of above 1100 nm. It can be concluded that the Si:Co layer can be prepared by Co implantation in Si followed by RTP method, and it is a promising material that can be used for intermediate band solar cells.