Porous silicon studied with time-resolved photoluminescence

Porous silicon has been studied with time-resolved photoluminescence, and g rowth as well as decay curves have been measured at several detection energ ies, with sample temperatures between 10 and 300 K. In the decay curves, th ree components are mainly observed, a small one which is very fast, with ti me scales of the order of nanoseconds or faster, the main component having time scales of the order of milliseconds, and a very small, very slow compo nent, with time scales of the order of seconds. The main components can in most-but not all-cases be fitted well with stretched exponentials containin g two fitting parameters. Of these, it comes out that the parameter account ing for disorder or the like depends only little upon detection energy and temperature, whereas the parameter accouting for the development in time de creases substantially for increasing temperature. The results are discussed .