Session E24 - Morphological Evolution During Epitaxial Growth:Semiconductors and Metals.
MIXED session, Tuesday morning, March 19
Room 123, America's Center

[E24.11] STM Study of Single Crystal Au Islands on MoS_2

S. Hong, J.D. Bielefeld, R.P. Andres, R. Reifenberger (Purdue University)

Single crystal, triangular-shaped nanometer-size Au islands were formed on MoS_2(0001) by vacuum depositing Au atoms onto heated MoS_2 substrates. From combined STM and TEM studies, the thin islands can best be described as nanoscale objects having the shape of tetrahedra with their tops cut off parallel to the base. Every face of the truncated tetrahedra is a Au(111) facet. The islands are found to have a preferred orientation relative to the MoS_2 substrate. I(V) measurements performed by placing an STM tip over the islands in UHV conditions reveal features that can be attributed to the MoS_2 substrate, indicating that the injected electrons are sensitive to the electronic structure of the buried interface. By pulsing the tip to high voltages, it is found that an entire Au island can be peeled from the substrate.