The interpretation of photoluminescence spectra (see the SCOUT manual for a PL introduction) is usually done in a simple and intuitive way. Peaks in measured spectra are discussed as directly reflecting the properties of electronic transitions. The following example of the PL spectrum of a porous silicon layer on a silicon substrate shows a main peak around  740 nm and a pronounced shoulder at 620 nm:

Clearly two electronic transitions are identified by a simple visual inspection.

However, interference phenomena in thin film systems cannot be handled intuitively. They must be treated using a spectrum simulation program like SCOUT in order to avoid misleading interpretations. In the following tutorial it is shown how the PL spectrum shown above can be analyzed on a more solid base taking into account reflection, re-absorption and interference effects.

In a fist step, a standard reflectance spectrum is taken to determine the layer thickness and the optical constants of the luminescent layer. Then a PL spectrum object is created in SCOUT and configured for the present case. Finally, the fit of the internal efficiency is performed leading to more reliable information about the electronic transitions.