Thin Solid Films, Vol.297, No.1-2, 132-134, 1997
Investigation of the Surface-Topography of Light-Emitting Nanostructures of Porous Si and the Related Photovoltaic Effect by Photoassisted Scanning-Tunneling-Microscopy
A porous Si surface was illuminated with an Xe lamp and scanning tunnelling microscopy (STM) was applied to observe the surface topography. High resolution photoassisted STM images reveal nanostructures of the order of 2-5 nm which is consistent with a dimensionality low enough for quantum confinement effects. Local I-V curves were measured using the spectroscopic mode of STM. Surface photovoltage (SPV) measurements show inhomogeneous charge effects on the surface of porous Si. There are both negative and positive SPV with discrete values observed on the same specimen.
Keywords:SILICON