The combining analysis of height and phase images in tapping-mode atomic force microscopy: a new route for the characterization of thiol-coated gold nanoparticle film on solid substrate

For the objective of future advice manufacture, the morphological change of the films formed on highly oriented pyrolytic graphite (HOPG) by evaporating 1-nonanethiol-protected 5 nm sized gold (Au) nanoparticle chloroform solution at various concentrations under chosen atmosphere conditions was investigated by tapping-mode atomic force microscopy (TM-AFM). The topography and phase images were simultaneously recorded to extract information on the film structures. The results show that the structure of the nanoparticle film, which varies from narrow belts, monolayer to bilayers with the increase of particle concentration, can be clearly distinguished by the combining analysis of TM-AFM topographical and phase images. This is further verified by corresponding TEM characterizations, too. The investigation demonstrates a new possible routine for the characterization of the devices based on nanoparticle film.