Fast, simple and efficient assembly of nanolayered materials and devices

Abstract

A new method of 'directed' self-assembly is demonstrated that has the potential to simply and quickly build nanostructured materials and devices. Called spin-spray layer-by-layer self-assembly (SSLbL), it is a modification of the well-known layer-by-layer method (LbL). Using SSLbL, it is possible to create and stack nanometre-thick, uniform layers containing a wide variety of different polymers, nanoparticles, or colloids in less than 25 s per bilayer, orders of magnitude faster than traditional LbL. This is done by modifying traditional dipping LbL to a system where carefully chosen volumes of polymer or colloidal solutions are sprayed directly on a rotating substrate. SSLbL is also much less wasteful of valuable nanoparticles and polymers than LbL. It is shown that in contrast to less than 1% material usage found in LbL, SSLbL has material usage efficiency up to 50%, and this can be further improved. Another direct result of the spin-spray modification is simple control of the in-plane structure of nanolayered films using masks, which is demonstrated. Such capability opens up the possibility of simply and inexpensively building complete nanocomposite devices with both vertical and lateral organization.