STM investigation of the island growth of gold on WS2 and WSe2

We have investigated the island growth of Au on the van der Waals surfaces of WS2 and WSe2 by STM. We show how the STM can be used to image as well as to manipulate nm-sized crystallites on these atomically smooth non-reactive substrates. The islands on the van der Waals planes are triangular in shape and are well aligned with the substrate lattice. Statistical analysis of our data yield subtle differences in the growth of Au on WS2 compared to WSe2