Electronic structures and the charge transfer of Au overlayer on Si 111/ surfaces

Electronic structures of 1=1-AurSi 111.systems have been calculated by the ab initio pseudopotential method in a local density approximation. Au and top-layer Si produce the bonding and a large charge transfer is seen from Si to Au. Comparing the results with and without on-top Si layer, it is shown that which Si layers release the charge depends on the number of surface Si dangling bonds. The relation between the charge transfer and the change of bond strength has also been clarified. q2000 Elsevier Science B.V. All rights reserved.