The photoluminescence emission in the 0.7-0.9 eV range from oxygen precipitates, thermal donors and dislocations in silicon

There is a wide set of literature reports that suggest that over-coordinate d oxygen or self-interstitials are, directly or indirectly, the chemical br idge between thermal donors, oxygen precipitates and dislocations. capable of supporting a common origin of their emission features in the 0.7-0.9 eV range. Finding the experimental proof of these suggestions was the aim of t his present work. which required both appropriate preparation of samples an d their careful optical. electrical and microscopical characterization. We were able to show not only that the photoluminescence emissions From oxi de precipitates could be correlated to their density and to the presence of closed dislocation rings around them. but also that the precursors of disl ocations are optically active as well. For samples thermally annealed in th e range of thermal donors. we were able to show that their optical activity seems to be correlated to a transition from a shallow donor level of therm al donors to a deep level of a CiO2 complex.