Defect-related photoluminescence in indium-implanted silicon

We measured photoluminescence (PL) spectra of In-implanted Si and observed a sharp line known as P-line and a broad band consisting of three emission bands. The dependence of the PL intensities on the annealing temperature and the excitation power density suggests that the interstitial In atoms are related to the P-line and the broad band. The dependence of the PL intensities on the sample temperature shows that the P-line and the broad band are due to the different origins. The comparison of the PL spectra for the different penetration depths of the excitation light indicates that the defects for the P-line are distributed deeper than those for the broad band. Considering the obtained results, we conclude that both the P-line and the broad band are due to the defect clusters with In atoms and that the structures of the defect clusters are different between the P-line and the broad band.