Surface scientific aspects in semiconductor electrochemistry

Abstract

Some of the fundamental properties of the reactive semiconductor–electrolyte interface are outlined and possibilities for electrochemical modification of semiconductor surfaces are discussed. The present status of investigating the physicochemical and morphological changes after (photoelectrochemical) processing is reviewed for selected examples. The accessibility of near surface changes by a selection of surface sensitive techniques is presented and the information obtained by ultrahigh vacuum ex situ methods such as high resolution electron energy loss spectroscopy (HREELS), and ultraviolet photoelectron spectroscopy (UPS) is compared with in situ techniques such as Fourier transform infrared spectroscopy (FTIR). The suitability of electrochemistry–atomic force microscopy (EC–AFM) to follow in situ the surface microtopographic changes during electrochemical processes is emphasised. Examples are presented on the electrochemically hydrogenated Si (111) surface and on monitoring in situ the changes at the silicon–silicon oxide–electrolyte interfacial region during current oscillations.