Photoluminescence excitation spectroscopy technique modified for studying structures with self-assembled Ge(Si)/Si(001) nanoislands

We describe a modification of photoluminescence excitation (PLE) spectroscopy that allows the process of light absorption and radiative recombination of charge carriers in structures with self-assembled Ge(Si)/Si(001) nanoislands to be studied. A specific feature of the proposed technique is that the photoluminescence (PL) of a sample is measured with both temporal and spectral resolution at various energies of exciting photons. Using the time-resolved PL measurements, it is possible to (i) separate PL signals related to the radiative recombination of carriers in the nanoislands and wetting layer and (ii) reveal parasitic signals related to the Raman scattering of exciting radiation in the silicon substrate.