THE ROLE OF ADSORBED ALKALI-METAL ATOMS IN THE ENHANCEMENT OF SURFACEREACTIVITY - A SCANNING-TUNNELING-MICROSCOPY STUDY OF LOW-COVERAGE K SI(111)7X7 SURFACES/
D. Gorelik et al., THE ROLE OF ADSORBED ALKALI-METAL ATOMS IN THE ENHANCEMENT OF SURFACEREACTIVITY - A SCANNING-TUNNELING-MICROSCOPY STUDY OF LOW-COVERAGE K SI(111)7X7 SURFACES/, The Journal of chemical physics, 108(23), 1998, pp. 9877-9884
Atomically resolved surface photovoltage imaging and tunneling barrier
imaging were performed with a scanning tunneling microscope to elucid
ate the nature of the initial adsorption state of potassium on room te
mperature Si(111)7 x 7 surface, which appears as a missing center Si-a
datom. No evidence was found to-support the fact that this adsorption
mode is charged. K islands start to grow (and accumulate at 7 x 7 doma
in boundaries) already at coverages as low as 4 x 10(12) cm(-2). These
islands may be responsible for the previously reported work function
lowering and enhanced chemical reactivity upon K deposition. (C) 1998
American Institute of Physics.