Correlation between PL emission band and growth of oxide layer on surface of silicon nanocrystallites

A systematic study of the correlation between surface oxidation and PL properties is important to clarify the nature of silicon nanocrystal. We prepared hydrogenated silicon nanocrystallites (nc-Si:H) by pulsed laser ablation, and observed IR absorption and PL spectra. Analysis of the Si-H bond gives us information on the local configuration of Si-O bond. The PL peak wavelength shifted from 800 ran to 400 nm with increasing the Si-O bond density. The frequency resolved PL spectra indicate that the PL peak is composed of at least three frequency regions. We found that PL peak is composed of 400, 700 and 800 nm bands by comparing frequency region and PL bands. The PL peak wavelength depends not on the composition but: on the thickness of surface oxide layer.