Microstructures and optical properties of surface and inside of silicon spheres

Surface and inside of silicon (Si) spheres prepared by a powder melting method were investigated. The lattice constant of the inside of Si spheres was larger than that of the surface of Si spheres, which was due to interstitial atoms trapped at gettering sites. To obtain the evidence for existence of the impurities, composition analysis was carried out. Florescence spectra of the surface and inside of Si spheres exhibited some information on impurities in both Si spheres.