Templated self-assembly of colloidal nanoparticles controlled by electrostatic nanopatterning on a Si3N4/SiO2/Si electret

Controlled self-assembly of colloidal nanoparticles onto an electrically nanopatterned electret film is presented (see figure; EFM: electrostatic force microscopy). An unprecedented reolution of 30 nm is achieved for both charge patterning and nanoparticle assembly. Furthermore, only a close-packed monolayer of nanoparticles is assembled, allowing better structural control and the possibility of forming hierarchical nanoparticle structures.