Adsorption of Li (K) on the Si(001)-(2×1) surface: Scanning-tunneling-microscopy study

Studies of low coverage adsorption of Li on Si(001): Observation of negative differential resistance and electron trapping

“…A highly buckled dimer seen next to the smallest cluster, L 1 , is incorporated in the larger cluster, L 2 . Hasegawa et al 6 reported that Li stabilizes the buckling of the dimers into small patches of c(4 ϫ 2) symmetry around the Li clusters, which is also observed here. We have also observed other types of clusters in the early stages of Li adsorption, although they are not as common as the two types in Fig.…”

“…One of the most investigated surfaces in this context is the technologically important Si͑001͒ surface and recently adsorption of the lightest of the alkalis, lithium, has generated much interest. [2][3][4][5][6][7][8][9][10][11][12] In a recent report, 12 we have presented angle-resolved photoemission spectroscopy ͑ARUPS͒ and STM results proposing that the half missing dimer defect ͑type C defect͒ acts as the initial adsorption site. Once the type C defects are occupied, Li adsorbs on top of the dimer atoms in agreement with earlier STM studies 6,7 and forms small clusters.…”

Ordering at Surfaces and Interfaces

“…They came to the conclusion that the most stable site forK appeared to be the cave site [34]. Also of interest is the STM investigation of Li adsorption on Si(100)2x1 in the very low coverage regime ('" 0.1 ML) in which a dangling bond site was claimed [77], in a way somewhat similar to hydrogen atoms known to also bind to the dangling bond. This behavior might look rather normal since Li is the smallest metal with a size and electronic structure close to that of hydrogen.…”

“…Also of interest is the STM investigation of Li adsorption on Si(100)2x1 in the very low coverage regime ('" 0.1 ML) in which a dangling bond site was claimed [77], in a way somewhat similar to hydrogen atoms known to also bind to the dangling bond. Another interesting feature of this STM study is that the Li mode of growth was found to be perpendicular to the Si dimer rows instead of the expected parallel mode [77]. Another interesting feature of this STM study is that the Li mode of growth was found to be perpendicular to the Si dimer rows instead of the expected parallel mode [77].…”

STM and DFT study on formation and characterization of Ba-incorporated phases on a Ge(001) surface

“…At coverages below 0.5 monolayer (ML) these elements were shown to form two adsorption structures on Si(001) and Ge(001)-namely the on-top and incorporated phases [15,19]. The on-top phase on Si(001) was observed for the room temperature (RT) adsorption of Ba, Li, or Sr atoms in the form of randomly distributed chains of the adatoms that run across the Si dimer rows [19][20][21][22][23]. The analogous phase formed by the Ba adatoms on Ge(100) was demonstrated to consist of the Ba ad-dimers [24].…”