Pentacene deposited onto a Ag(111) surface at 300 K is studied using scanning tunneling microscopy at temperatures of 300 K and 50 K. At 300 K, ordered pentacene structures nucleate at Ag step edges (<i>Phys. Rev. B</i> <b>2005</b>, 72, 115430) and are surrounded by a pentacene phase without evident order. The ordered structures visible at 300 K are revealed as bilayer structures from their coverage-dependent size evolution and molecularly resolved images of domain boundaries, recorded at 50 K. At this reduced temperature, two different monolayer phases with long range order and commensurate with the Ag(111) surface lattice further emerge . These two monolayer phases exhibit comparable (0.7 vs 0.8 molecule/nm<sup>2</sup>) packing densities, but distinct intermolecular registration and pentacene alignment with respect to the silver sublattice.<br><br>
Citation: Journal of Physical Chemistry C
Pub Type: Journals
"adsorption", "pentacene", "scanning tunneling microscopy"