Sacrificial layer electrophoretic deposition of free-standing multilayered nanoparticle films

摘要

Sacrificial layer electrophoretic deposition (SLED) is a technique to assemble nanoparticles that yields free-standing, multilayered nanoparticle films with macroscopic lateral dimensions after the sacrificial layer is dissolved.rnColloidal nanoparticles (NPs) have been the focus of far-reaching research pursuits due to their attractive material-dependent and size-dependent electronic, optical and magnetic properties. The NPs typically comprise an inorganic core material coated with surface-passivating organic ligand molecules that, in part, determine their solubility in a given solvent. Solution-phase NPs have been targeted for applications such as fluorescent tagging of cells, drug delivery, and magnetic recording media. Further applications may be accessed by forming dry casts of the NPs. Multilayered thin films of NPs have been featured in solid-state lighting, magnetic storage, and catalytic devices. Harnessing colloidal NPs to produce new electronic devices is desired because they can be deposited into solid thin films using wet processes, which offer significant cost advantages over conventional semiconductor fabrication processes. Many of these wet processes, however, have acknowledged shortcomings, such as imposing requirements on the film deposition surface and offering limited capacity to pattern films laterally. With a technique to assemble NPs into free-standing films that are robust enough to be transferred to arbitrary substrates, the barriers to using NPs in engineered devices would be lowered significantly.