Cycloaddition on Ge(100) of the Lewis Acid AlCl3

The adsorption and decomposition of AlCl 3 on Ge(100) was studied using scanning tunneling microscopy (STM) and high-resolution core-level photoemission spectroscopy (HRCLPES). Through the analysis of the STM image and Ge 3d and Cl 2p core-level spectra of AlCl 3 on Ge(100), we found that an AlCl 3 molecule reacts with two Ge atoms via a cycloaddition reaction, which forms Cl−Ge and AlCl 2 −Ge without breaking AlCl 3 . Additionally, by considering valence shell electron pair repulsion (VSEPR) arguments, the effect of molecular structure on the surface chemistry was explained. To our knowledge, the adsorption of Lewis acid molecules on a semiconductor surface has not been studied in detail. These are the first results for the adsorption structures of Lewis acid molecule on Ge(100).