We present results obtained by in situ scannning tunneling microscopy which show the morphological details of the transition from layer by layer growth to three-dimensional island growth during electrodeposition. Two epitaxial layers of Ag are sequentially formed prior to the heterogeneous nucleation of three-dimensional Ag crystallites which preferentially develop on steps. The 3D growth initiates when 2D protrusions growing on the completed second adlayer achieve a critical dimension of order 20-50 nm. Our observations and analysis indicate that the growth transition may be kinetically determined by adatom migration over descending steps.
ASJC Scopus subject areas
- Physics and Astronomy(all)