Electron powder ribbon (EPR) plates elaborated from 99.9%-99.9999% pure silicon powder show crystallographic structure favourable to the achievement of nanocrystallites which are at the origin of luminescence. Fourier transform IR spectrometry and secondary ion mass spectrometry observations correlated with the comparative luminescence of porous layers produced on single-crystal and EPR polycrystalline silicon are carried out. The luminescence spectra are controlled by a combination of the electrochemical parameters and the starting material resistivity. An electroluminescent cell is elaborated and microcrystalline structures are obtained for sensor applications using the adsorption process (e.g. moisture measurements).