Chapter 22 Mechanism of Influence of Aminoacid Adsorption on Photoluminescence of Nanoporous Silicon

摘要

Photoluminescence (PL) spectra of porous silicon with adsorbed molecules of aminoacids (methionine and glycine) were investigated at room temperature. It was found that the layers of porous silicon (PSi) with porosity about 40% have more intensive photoluminescence (PL) than that with porosity in range of 50-80 %. A short-wave shift of PL spectra under methionine adsorption was observed. This PL shift was accompanied by a decrease in the size of nc-Si due to the local oxidation of Si nanocrystals (nc-Si) during the interaction with adsorbed methionine molecules. In contrast to these phenomena, the adsorption of glycine leads to increase of PL intensity almost two times and to shift of the PL peak to the long-wave region (from 660 to 700 nm) caused by an increase in the average size of nc-Si as a result of the recovery process on PSi surface by glycine molecules. The differences in PL properties between PSi and PSi covered with the layer of carbon nanotubes are also discussed.