PROPERTIES OF POROUS SILICON LAYERS STUDIED BY VOLTAMMETRIC OXIDATION

The existence of an outer cracked layer and an inner more structured p orous layer has been observed in electrochemically obtained porous sil icon when drying procedures ale carried out, The changes in the charge transferred to the porous structure during voltammetric oxidation, th e interference fringes obtained by Fourier-transform infrared spectros copic measurements, and scanning electron microscopy micrographs confi rm the existence of this double layer Also, drying procedures and volt ammetric oxidations drastically affect the intensity and wavelength of the peak maximum in the pbotoluminescence spectrum. The evolution of the luminescent properties is explained by the introduction of nonradi ative recombination centers. (C) 1996 American Institute of Physics.