Abstract
Materials with a high and tunable refractive index are attractive for nanophotonic applications. In this contribution, we propose a straightforward fabrication technique of high-refractive index surfaces based on self-assembled nanostructured block copolymer thin films. The selective and customizable metal incorporation within out-of-plane polymer lamellae produces azimuthally isotropic metallic nanostructures of defined geometries, which were analysed using microscopy and small-angle X-ray scattering techniques. Variable-angle spectroscopic ellipsometry was used to relate the geometrical parameters of the metallic features and the resulting refractive index of the patterned surfaces. In particular, nanostructured gold patterns with a high degree of homogeneity and a gold content as low as 16 vol% reach a refractive index value of more than 3 in the visible domain. Our study thus demonstrates a new route for the preparation of high refractive index surfaces with a low metal content for optical applications.
Highlights
We propose a straightforward fabrication technique of high-refractive index surfaces based on self-assembled nanostructured block copolymer thin films
Our study demonstrates a new route for the preparation of high refractive index surfaces with a low metal content for optical applications
Of particular interest is the design of high refractive index surfaces, which are crucial for a variety of applications, ranging from optoelectronics to photolithography.[11,12]
Summary
P, and their diameter, d, are strongly correlated following the relationship: d1⁄4. Variable-angle spectroscopic ellipsometry measurements are used to probe the optical properties of the gold decorated surfaces in order to retrieve the refractive index as a function of the density, shape and spatial arrangements of the NPs. The PS-b-P2VP, with Mn (PS) 1⁄4 102.0 kg molÀ1 and Mn (P2VP) 1⁄4 97.0 kg molÀ1, was purchased from Polymer Source Inc. and used as received. The optical study of the lms deposited on silicon-wafers was performed using variable angle spectroscopic ellipsometry (VASE) in re ection with a phase modulated spectroscopic ellipsometer (UVISEL, from Horiba Scienti c) on the spectral range [0.6–4.8 eV or 258–2000 nm]. Spectroscopic ellipsometry data measured on the bare silicon substrate were analysed using the Si and SiO2 tabulated dielectric functions and yielded a thickness value (2.0 nm) for the native silica layer on the surface, which was xed in the further analysis. The goodness of the ts was assessed by the value of the usual c2 parameter
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
