Electronic excitations induced modifications of structural and optical properties of ZnO–porous silicon nanocomposites

The influence of swift heavy ion (SHI) irradiation on structural and photoluminescence (PL) properties of ZnO nanocrystallites deposited into porous silicon (PS) templates by the sol–gel process was studied. The ZnO/PS nanocomposites were irradiated using 120 MeV Au ions at different fluences varying from 1 × 1012 to 1 × 1013 ions/cm2. The intensity of the X-ray diffraction peaks is suppressed at the high fluence, without evolution of any new peak. The PL emission from PS around 700 nm is found to decrease with increase in ion fluence, while the PL emission from deep level defects of ZnO nanocrystallites is increased with ion fluence. At the highest fluence, the observation of drastic increase in PL emission due to donor/acceptor defects in the region 400–600 nm and suppressions of XRD peaks could be attributed to the defects induced structural modifications of ZnO nanocrystallites.