STM STUDIES OF P-SI(111) SUBSTRATE IN AIR AND IN ELECTROLYTIC ENVIRONMENT

Scanning tunneling microscopy was used to study p-Si(111) surfaces in electrolyte solution and in air as well. The dependence of STM images on the sign and magnitude of tunneling bias voltage, as well as on the surface environment, was detected. This dependence was correlated with the electronic propErtles of p-Si(111) surfaces. It is proposed that electrochemical formation of SiOx and Si-OH surface compounds induces surface states in the band-gap of p-Si(111) at approximately 0.25 eV from the edge of the valence band at the surface. © 1990.