EXCITATION-SPECTRA OF THE VISIBLE PHOTOLUMINESCENCE OF ANODIZED POROUS SILICON

Porous silicon samples, photoluminous in orange, pink or greenish yellow, were formed by anodization. The shapes and wavelength positions of their photoluminescence peaks were not influenced by the "citation wavelength. The photoluminescence intensity at any wavelength between 520 nm and 800 nm varied as a function of the excitation wavelength in accordance with the imaginary part of the spectral refractive index of bulk silicon. Thus, the excitation process responsible for the visible photoluminescence of porous silicon seems to be bulk-silicon-like.