Enhanced Hybridization and Nanopatterning via Heated Liquid-Phase Infiltration into Self-Assembled Block Copolymer Thin Films

Abstract

Organic–inorganic hybrids featuring tunable material properties can be readily generated by applying vapor- or liquid-phase infiltration (VPI or LPI) of inorganic materials into organic templates, with resulting properties controlled by type and quantity of infiltrated inorganics. While LPI offers more diverse choices of infiltratable elements, it tends to yield smaller infiltration amount than VPI, but the attempt to address the issue has been rarely reported. Here, we demonstrate a facile temperature-enhanced LPI method to control and drastically increase the quantity and kinetics of Pt infiltration into self-assembled polystyrene-block-poly­(2-vinylpyridine) block copolymer (BCP) thin films. By applying LPI at mildly elevated temperatures (40–80 °C), we showcase controllable optical functionality of hybrid BCP films along with conductive three-dimensional (3D) inorganic nanostructures. Structural analysis reveals enhanced metal loading into the BCP matrix at higher LPI temperatures, suggesting multiple metal ion infiltration per monomer of P2VP. Combining temperature-enhanced LPI with hierarchical multilayer BCP self-assembly, we generate BCP-metal hybrid optical coatings featuring tunable antireflective properties as well as scalable conductive 3D Pt nanomesh structures. Enhanced material infiltration and control by temperature-enhanced LPI not only enables tunability of organic–inorganic hybrid nanostructures and properties but also expands the application of BCPs for generating uniquely functional inorganic nanostructures.

Resolving Triblock Terpolymer Morphologies by Vapor-Phase Infiltration

“…[27][28][29][30][31][32][33][34][35][36][37] The infiltration process proceeds via sorption (diffusion) and block-selective reaction of vapor-phase organometallic precursors into the polymer blocks with suitable reactive moieties to generate infused inorganic materials within the target BCP microdomains. [38][39] The hybrid nanocomposite thus formed can also be converted to an inorganic nanostructure inheriting the original structure of the polymer microdomains, 34,36 not only producing various functional nanostructures in a simple process but also enabling all-organic BCP morphologies to be fully resolved. 31 ALD of metal oxide precursors into cylinder-and gyroidforming BCPs has been used to generate 1D and 3D nanostructures for a broad variety of nanotechnologies such as gas sensors, solar cells, photocatalysts, and pattern transfer masks.…”

Green Nanofabrication Opportunities in the Semiconductor Industry: A Life Cycle Perspective

“…Deposition of inorganic materials into polymer brush matrix or self-assembled nanodomains of BCPs can also be achieved using liquid deposition processes such as spin coating [ 11 , 18 , 130 , 131 ]. Other methods of metal inclusion are ALD and low temperature vapour phase deposition and sequential infiltration (SIS) [ 12 , 62 , 132 ].…”

Multifunctional Structured Platforms: From Patterning of Polymer-Based Films to Their Subsequent Filling with Various Nanomaterials

“…Common polymeric materials that can be used to create nanostructures by selfassembly include polystyrene-b-poly(vinyl benzyl azide) [208], polystyrene-b-poly(vinyl pyridine) [233], polystyrene-arm-poly(2-vinylpyridine)-arm-polyisoprene (PS-arm-P2VParm-PI) [200], maltoheptaose-b-polystyrene [217], polystyrene-b-polyethylene oxide [207], and many more [195,199,209,212,215,219,221,225,226,231,232]. That is why BCPs are considered highly representative materials in innovative applications such as smart materials [211], 2D photonic crystals [200], graphene nanocomposites [202], or information storage devices [199], just to name a few.…”

“…However, very often, such a patterning process does not stop here, and these resulting patterns are being further used as templates for subsequent pattern transfer [234,237]. This is needed in order to fabricate 3D structure relief patterns [233,238] of sub-10 nm features [205] on large areas [206,234] on various other materials/substrates.…”

“…The transfer of (flexible [237]) surface relief patterns on graphene [234,237] or other solid, often functionalized [239], substrates [206,240] can be done by employing additional etching or infiltration [233,238,241] procedures, which is followed by the controlled deposition of thin films of various materials [205,241,242], including metals [243] and metal oxides [244]. Examples of etching procedures include UV ozone [243], oxygen [241,243], nitrogen [241], or other types [239,241] of plasma etching, CO 2 and Cl 2 /O 2 reactive ion etching [205], etching in alkaline solutions [204]), etc.…”