Self-Assembled Monolayers of Dipolar Nonlinear Optical Nickel(II) Molecules on the Si(100) Surface with Nanoscale Uniformity

The synthesis and structure of a dipolar nonlinear optical bis(salicylaldiminato)NiII-derivatized Schiff base complex chemisorbed on H-terminated Si(100) surfaces is reported. The existence of a monolayer of the derivatized complex chemisorbed on the Si(100) surface is unambiguously confirmed by high-resolution core-level XPS and AFM/SNOM analyses. The comparison between the optical SNOM images highlights the contribution of the monolayer to the local reflectivity of the sample. Angle-resolved XPS data indicate the presence of chlorine head atoms on the monolayer surface. Altogether, XPS and AFM/SNOM data suggest the formation of a nanoscale uniform, homogeneous, complete, ordered monolayer self-assembled on the Si(100) surface.