Radial Distribution of Active Impurities in Individual In situ Boron-Doped Silicon Nanowires: A Raman Scattering Study

Abstract

The radial distribution of electrically active B in individual in situ B-doped Si nanowires (SiNWs) grown by the vapor liquid solid (VLS) process is studied by combining micro-Raman spectroscopy and wet chemical etching. The etching of the surface layer results in significant changes in the Raman spectra; Fano-type asymmetry, which is a characteristic of heavily doped p-type Si, disappears and the spectra become almost symmetric. The Raman data reveal that the as-grown B-doped SiNWs consist of a heavily B-doped shell and an almost intrinsic core.