Abstract:
In present work, we studied the mechanisms of dissolution of porous silicon nanoparticles (PSi NPs) during their incubation in model liquids, i.e. water and phosphate buffered saline (PBS) at 37$^\circ$ Ñ. The methods of transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy, and Raman spectroscopy were used. According to TEM images, PSi NPs consist of silicon nanocrystals (nc-Si) 2–10 nm in size and pores. It is shown that incubation of PSi NPs in water leads to enhancement of their PL, accompanied by a slight decrease in the size of nc-Si, which is associated with the passivation of defects and stabilization of the oxide shell of nanocrystals. During incubation in PBS, a significant quenching of PL and disappearance Raman signal of the PSi NPs took place. That indicates rapid dissolution of PSi NPs. We presented phenomenological model describing how quantum-confinement effect affects properties of nc-Si during their dissolution.