On the influence of dislocations on the luminescence of Si : Er

We have studied by electrical and optical methods the properties of the defects to possibly identify which ones affect the luminescence of the material. We have characterized Er-doped Si samples grown by the Liquid Phase Epitaxy (LPE) method, a relatively simple and inexpensive technique, by means of photoluminescence (PL), cathodoluminescence, EXAFS and deep level transient spectroscopy. The optical methods reveal the presence of two emission bands which coincide with the lines labelled D1 and D2, attributed to dislocations. Since line D1 fortuitously coincides within a few meV with the energy of the transition I-4(15/2) --> I-4(13/2) of Er3+, it could at least partially cover the Er-related emission. Furthermore, as Er and O could both interact with dislocations, the dislocation optical activity might be influenced by their presence and play a significant role in the material overall luminescence.