EXCITATION SPECTROSCOPY OF ANODICALLY OXIDIZED POROUS SILICON

Photoluminescence (PL) and photoluminescence excitation (PLE) studies are carried out on porous silicon (PS) layers anodically oxidized in N H4NO3-ethylenglycol electrolyte. PLE spectra reveal monocrystalline si licon like features after removing the oxide shelf of crystallites by chemical etching. Its reconstruction during oxidation in air atmospher e seems to increase mechanical stresses in silicon nanocrystallites. A s a result, the PLE spectra, absorption and emission properties of PS are changed considerably.