Interfacial Structure imaging of Pentacene/Si(111) by model- independent method

Synchrotron x-ray reflectivity is utilized to study the Pentacene/Si(111) interfacial structure in the direction normal to the surface. Model-independent algorithm is used to analyze the reflectivity data to extract the electron density profile. It indicates two partially ordered layers along the interfacial normal with thickness $\sim $0.6 nm and an interfacial water layer $\sim $0.9 nm as we reported in our previous work. A pentacene monolayer $\sim $1.6 nm can also be revealed.