Room temperature adsorption of aniline (C6H5NH2) on Si(100)(2x1) observed with scanning tunneling microscopy

The chemisorption of aniline (C6H5NH2) on Si(100)(2 x 1) at room temperature has been studied for the first time with scanning tunneling microscopy (STM) and spectroscopy (STS). The STM images reveal that aniline adsorbs on Si(100)(2 x 1) and forms regions of moderately ordered p(2 x 2) or c(4 x 2) structures. The STS results show a quenching of the silicon surface states after adsorption and an increased energetic gap between occupied and unoccupied surface slates if compared with the clean surface. The first occupied state coincides with the corresponding peak in the ultraviolet photoelectron spectrum. (C) 1998 Elsevier Science B.V. All rights reserved.