Surface photovoltage studies of Si nanocrystallites prepared by electrochemical etching

Nanocrystalline Si has been prepared by anodic etching of Si in an electrolyte consisting of ethanol and HF. The structure and surface morphology have been studied using transmission electron microscopy which reveal the cubic structure and porous morphology of Si nanocrystals (NCs). Electrochemical etching has resulted in surface oxidation of Si NCs as confirmed from X-ray photoelectron spectroscopic measurements. The average size of the Si NCs has been estimated from the line broadening analysis of the Raman scattering. Unique optical transitions associated with porous Si/SiO2 quantum well (QW) like structure has been investigated by surface photovoltage (SPV) measurements.