We report the photosensitization of crystalline silicon via energy transfer using covalently attached protoporphyrin IX (PpIX) derivative molecules at different distances via changing the diol linker to the surface. The diol linker molecule chain length was varied from 2 carbon to 10 carbon lengths in order to change the distance of PpIX to the Si(111) surface between 6 Å and 18 Å. Fluorescence quenching as a function of the PpIX–Si surface distance showed a decrease in the fluorescence lifetime
