Naphthalene adsorption on Si(1 1 1)-7 × 7

The adsorption of naphthalene on Si(1 1 1)-7 × 7 at room temperature was studied using STM and DFT calculations. It is proposed that the major, if not exclusive, binding configuration of the adsorbed naphthalene involves the formation of covalent bonds between two opposite C atoms from one of the rings in naphthalene with an adjacent adatom-rest atom pair on the substrate. Combined data from STM and DFT studies shows that the chemisorption of naphthalene causes an increase in the charge density of the neighboring dangling bond sites that in turn enhance their reactivities with a naphthalene molecule. The faulted center and unfaulted corner adatoms are, respectively, the most and least reactive sites for naphthalene while the relative reactivities of the faulted corner and unfaulted center adatoms exhibit dependence on the naphthalene coverage.