MOLECULAR IMAGING AND LOCAL-DENSITY OF STATES CHARACTERIZATION AT THESI(111) NAOH INTERFACE/

We present in situ scanning tunneling microscopy (STM) images with the resolution of isolated =Si-OX groups on H-Si(111) in NaOH solutions w ith or without isopropyl alcohol [X=H or -CH(CH3)(2)]. The comparison of STM with geometric contours shows that the electronegativity of OH ligands enhances the local density of states and generates a surface p otential distribution. The dependence of both observations with the ra dical X and the mechanisms of grafting are discussed.