Self-assembly of 2D ordered silver nanoparticle arrays on triblock copolymer templates

Poly (styrene-b-butadiene-b-styrene) (SBS) triblock copolymer templates which present 2D ordered perforated pattern have been prepared by solvent-induced order-disorder phase transition method. By low energy clusters beam deposition (LECBD) apparatus silver clusters have been obliquely deposited onto the SBS copolymer templates. The morphology of the samples has been characterized by a tapping-mode AFM. It is shown that silver nanoparticles form 2D ordered arrays and the interparticle distance of the 2D ordered array is comparable to the particle size. Optical absorption spectra reveal that the surface plasmon resonance (SPR) of 2D ordered silver nanoparticle arrays occurs at 436.1nm. It is mainly due to the interaction of siver clusters with the exciting light at their surface plasmon frequency and electrodynamic interactions between silver clusters. The surface-enhanced Raman spectroscopy(SERS) spectrum shows the electric field enhancement that occurs in the vicinity of interacting silver nanopraticles. Hence the assembly of metal-copolymer nanostructure transcends the spatial limits of lithography and provides a promising route to achieve well ordered nanostructures.