Correlation between surface oxide and photoluminescence properties of Si nanoparticles prepared by pulsed laser ablation

Hydrogenated silicon nanoparticles were prepared by pulsed laser ablation (PLA) of Si target in hydrogen gas. We observed native oxidation process for 250 days by infrared (IR) absorption measurement and investigated correlation between native oxidation and photoluminescence (PL) properties. We found three PL peak regions, around 800 nm, 600–700 nm and 400–500 nm. These PL peak wavelengths depended on the Si-O bond density and remarkable correlation with composition of the oxide layer was not observed. The native oxidation is a passive method to modify the surface. We propose plasma surface treatment as an active method. The PL wavelength varied by the surface treatments due to suppression of native oxidation. The surface modification is an important technique to control PL peak wavelength of silicon nanoparticles.