Fullerene monolayer formation by spray coating

Many large molecular complexes are limited in thin film applications by their insufficient thermal stability, which excludes deposition via commonly used vapour phase deposition methods. Here we demonstrate an alternative way of monolayer formation of large molecules by a simple spray coating method under ambient conditions. This technique has been successfully applied on C60 dissolved in toluene and carbon disulfide. Monolayer thick C60 films have been formed on graphite and gold surfaces at particular deposition parameters, as confirmed by atomic force and scanning tunnelling microscopies. Structural and electronic properties of spray coated C60 films on Au(111) have been found comparable to thermally evaporated C60. We attribute the monolayer formation in spray coating to a crystallization process mediated by an ultrathin solution film on a sample surface.