Pentacene Monolayer Trapped Between Graphene and Substrate

Self-assembled pentacene monolayer can be fabricated between solid-solid interface between few-layer graphene (FLG) and mica substrate, through a diffusion-spreading method. By utilizing a transfer method that allows us to sandwich pentacene between graphene and mica, followed by controlled annealing, we enables the diffused pentacene to be trapped in the interface and lead to the formation of a stable monolayer.  We found that the formation of monolayer is kinetically favored by using a 2D Ising lattice gas model under graphene-substrate interface. This kinetic Monte Carlo simulation results indicates that, due to the graphene substrate enclosure, the spreading of the first layer proceeds faster than the second layer, as the kinetics favors the filling of void by molecules from the second layer.  This graphene assisted monolayer assembly method provides a new venue for fabrication of two-dimensional monolayer structures.