Patterned Diblock Co-Polymer Thin Films as Templates for Advanced Anisotropic Metal Nanostructures.

Stephan V Roth,Philipp Bremer,Michael A Rübhausen,Bastian Besner,Peng Zhang,Nick J Terrill,Matthias Schwartzkopf,Peter Müller-Buschbaum,Shun Yu,Ezzeldin Metwalli,Yuan Yao,Dieter Rukser,Ralph Döhrmann,Johannes F H Risch,Paul A Staniec,Gonzalo Santoro,Torsten Boese

doi:10.1021/am507727f

Abstract

We demonstrate glancing-angle deposition of gold on a nanostructured diblock copolymer, namely polystyrene-block-poly(methyl methacrylate) thin film. Exploiting the selective wetting of gold on the polystyrene block, we are able to fabricate directional hierarchical structures. We prove the asymmetric growth of the gold nanoparticles and are able to extract the different growth laws by in situ scattering methods. The optical anisotropy of these hierarchical hybrid materials is further probed by angular resolved spectroscopic methods. This approach enables us to tailor functional hierarchical layers in nanodevices, such as nanoantennae arrays, organic photovoltaics, and sensor electronics.

Highlights

The tailoring of metal nanoparticles layers[1] and hybrid materials plays a crucial role in modern advanced material science.[2−4] The demand ranges from hydrophobic surfaces and 5 flexible sensors[6,7] to organic photovoltaics (OPV)[8,9] and magnetic storage media.[10]
I.e., deposition direction normal to the substrate, allows for installing radially symmetric nanoparticles, a process used for SERS18 and catalysis.[26−28] In contrast, for sensor applications as well as catalysis, the size and length scale of the nanoparticles is on the order of a few nanometers
The small shoulders at qy ≈ 0.14 nm−1 stem from the phase separated structure, which is seen in the atomic force microscopy (AFM) images presented in Figure 3a and are discussed later

Summary

Introduction

The tailoring of metal nanoparticles layers[1] and hybrid materials plays a crucial role in modern advanced material science.[2−4] The demand ranges from hydrophobic surfaces and 5 flexible sensors[6,7] to organic photovoltaics (OPV)[8,9] and magnetic storage media.[10] The related objective is to combine the tunable nanostructure of diblock copolymeric materials[11,12] with the selective interaction of metals with different polymer materials.[13−15]. The applications of metallic layers cover catalytically active layers[16] via colloidal contacts[17] or nanostructures for sensor applications[6,18] and single electron devices.[19] Often, spray deposition[17,20] and vacuum deposition methods such as molecular beam epitaxy,[21] vapor deposition,[22,23] and sputter deposition[24,25] are employed to achieve the installation of the metallic layer. This controlled deposition can even be combined with quantum dots to position plasmonic structures.[40]

Methods

Results

Conclusion