Structure–Function Correlations in Sputter Deposited Gold/Fluorocarbon Multilayers for Tuning Optical Response

Abstract

A new strategy to nanoengineer gold/fluorocarbon multilayer (ML) nanostructures is reported. We have investigated the morphological changes occurring at the metal–polymer interface in ML structures with varying volume fraction of gold (Au) and the kinetic growth aspect of the microscale properties of nano-sized Au in plasma polymer fluorocarbon (PPFC). Investigations were carried out at various temperatures and annealing times by means of grazing incidence small-angle and wide-angle X-ray scattering (GISAXS and GIWAXS). We have fabricated a series of MLs with varying volume fraction (0.12, 0.27, 0.38) of Au and bilayer periodicity in ML structure. They show an interesting granular structure consisting of nearly spherical nanoparticles within the polymer layer. The nanoparticle (NP) morphology changes due to the collective effects of NPs diffusion within ensembles in the in-plane vicinity and interlayer with increasing temperature. The in-plane NPs size distinctly increases with increasing temperature. The NPs become more spherical, thus reducing the surface energy. Linear growth of NPs with temperature and time shows diffusion-controlled growth of NPs in the ML structure. The structural stability of the multilayer is controlled by the volume ratio of the metal in polymer. At room temperature, UV-Vis shows a blue shift of the plasmon peak from 560 nm in ML Au/PTFE_1 to 437 nm in Au/PTFE_3. We have identified the fabrication and postdeposition annealing conditions to limit the local surface plasmon resonance (LSPR) shift from ΔλLSPR = 180 nm (Au/PTFE_1) to ΔλLSPR = 67 nm (Au/PTFE_3 ML)) and their optical response over a wide visible wavelength range. A variation in the dielectric constant of the polymer in presence of varying Au inclusion is found to be a possible factor affecting the LSPR frequency. Our findings may provide insights in nanoengineering of ML structure that can be useful to systematically control the growth of NPs in polymer matrix.

Structural Transition and Interdigitation of Alkyl Side Chains in the Conjugated Polymer Poly(3-hexylthiophene) and Their Effects on the Device Performance of the Associated Organic Field-Effect Transistor

“…We should mention here that although the x-ray diffuse scattering technique used here can provide quantitative information on surface morphologies of thin films, − the grazing-incidence small-angle x-ray scattering (GISAXS) is much preferable for characterizing nanoscale morphologies in thin films and their kinetic and dynamic behaviors. − A combination of GISAXS and 2D GIXS is a powerful tool to characterize both larger-scale domains and smaller-scale crystalline structures, which are strongly related to the device performance in organic thin-film systems. − …”

Highly Permeable Fluorinated Polymer Nanocomposites for Plasmonic Hydrogen Sensing

“…As a result, the attention is increasingly shifting to more cost-effective optical sensors that can be realized with scalable production methods. 17 , 18 Therefore, we argue that it would be particularly desirable to harness the wealth of readily available polymer nanocomposite processing methods, such as solution processing, 19 , 20 sputter deposition, 21 − 23 and especially bulk processing methods, such as melt compounding. 16 , 24 …”

Trilayer Composite System Based on SiO2, Thiol-Ene, and PEDOT:PSS. Focus on Stability after Thermal Treatment and Solar Irradiance

“…Layered composites are of interest as each layer usually exhibits different functional properties, which add up to the whole system to meet the specific practical requirements for a certain application [ 1 , 2 , 3 ]. Functional multilayers are common in optics [ 4 ], electronics [ 5 ], and sensors [ 6 ]. Moreover, there has been a recent growing interest in advanced functional multilayers related to emerging applications in organic electronics [ 7 , 8 ].…”