integration-light-trapping-silver-nanostructures-hydrogenated

Integration of Light Trapping Silver Nanostructures in Hydrogenated Microcrystalline Silicon Solar Cells by Transfer Printing

One of the potential applications of metal nanostructures is light trapping in solar cells, where unique optical properties of nanosized metals, commonly ...

National Institute of Advanced Industrial Science and Technology, Koriyama, Fukushima, Japan

Oxidative ligand coupling of organoborates was catalyzed by VO(OEt)Cl(2) under oxygen atmosphere, which provides a versatile method for the selective synthesis of symmetrical or unsymmetrical biaryls.

Oxovanadium(v)-catalyzed oxidative biaryl synthesis from organoborate under O2.

A stamp-based nanoscale patterning technique of organic monolayers, termed catalytic stamp lithography, is described. The surface of poly(dimethylsiloxane) was patterned with catalytic Pd nanoparticles (NPs) via the use of self-assembled block copolymers. Using this catalytic stamp, catalytic hydrosilylations of terminal alkenes/alkynes were performed on H-terminated Si(111) or Si(100) surfaces to create nanoscale patterns of organic monolayers. Since the reaction takes place exclusively underneath the patterned Pd NPs (localized catalysis), the pattern formation is less susceptible to ink diffusion and stamp deformation, even at this sub-100 nm scale. A range of different molecular inks can be utilized to produce monolayer patterns of different chemical functionalities, and the stamps can be reused multiple times. The potential utility of this kind of chemically patterned surfaces as the basis for more complicated nanoarchitectures was demonstrated through gold nanoparticle capture, with a thiol-terminated nanopatterned silicon surface.

Catalytic stamp lithography for sub-100 nm patterning of organic monolayers.

Developing a method to pattern organic molecules, particularly on the sub-100-nm scale, is of wide interest in current nanoscience for a broad range of technological applications. Because of the efficiency and simplicity of soft lithography, here we describe in detail the process for synthesizing and applying catalytic stamp lithography, a process that can easily produce sub-100-nm patterns on surfaces; in this work, the approach is demonstrated on silicon. Catalytic stamps were fabricated through a two-step procedure in which the nanoscale pattern of catalysts is produced via a self-assembled block-copolymer-templated synthesis of metallic nanostructures on SiO(x)/Si supports, followed by the production of the poly(dimethylsiloxane) (PDMS) stamp on top of the as-patterned metals. Simply peeling off the as-formed PDMS stamp removes the metallic nanostructures, leading to the functional stamp. Two different patterns, pseudohexagonal and linear Pt nanoarrays, were produced from a single block copolymer, PS(125000)-b-P2VP(58500), by controlling the morphology of thin-film templates through tetrahydrofuran vapor annealing. When terminal alkenes, alkynes, or aldehydes with different functionalities were used as molecular inks, these Pt nanopatterns on catalytic stamps were translated into corresponding molecular arrays on Si(111)-H and Si(100)-H(x) surfaces because catalytic hydrosilylation took place exclusively underneath patterned Pt nanostructures. With this straightforward approach, the resolution limit of conventional microcontact printing (approximately 100 nm) could be downsized to a sub-20-nm scale, while maintaining the advantages of stamp-based patterning (i.e., large-area, high-throughput capabilities and low cost).

Nanoscale patterning of organic monolayers by catalytic stamp lithography: scope and limitations.

Soft lithographic sub-100 nm chemical patterning was demonstrated on organic monolayer surfaces using poly(dimethylsiloxane)-based stamps decorated with Pd nanostructures, structures termed "catalytic stamps". Chemically reactive azide or alkene functionalities were incorporated on oxide-capped silicon surfaces and utilized for patterning via Pd-catalyzed hydrogenation or Heck reactions. The catalytic stamps were soft lithographic stamps based on PDMS with embedded nanoscale palladium catalysts, prepared via block copolymer-based templating. Nanoscale chemical patterns were readily generated on the azide or alkene precursor surfaces simply by applying the Pd catalytic stamps and the reactive molecule, the molecular ink, to the surface, thanks to the highly localized catalytic transformations induced by the patterned, immobilized solid Pd catalysts. A series of successful postfunctionalization reactions on the resulting patterned surfaces further demonstrated the utility of this approach to construct novel designs of nanoarchitectures, with potentially unique and innovative properties.

Building upon patterned organic monolayers produced via catalytic stamp lithography.

A method to fabricate metal nanostructures by transfer printing, applicable to textured surfaces, is described. The key is the use of self-assembled polystyrene-block-poly-2-vinylpyridine thin films as binding layers. The plasmonic properties of the obtained metal (Ag) nanostructures showed the potential of this method in the design of novel devices.

Article	Year
Oxovanadium(v)-catalyzed oxidative biaryl synthesis from organoborate under O2. Chemical communications (Cambridge, England)\| PubMed ID: 17146521	2006
Catalytic stamp lithography for sub-100 nm patterning of organic monolayers. Journal of the American Chemical Society\| PubMed ID: 19063631	2008
Nanoscale patterning of organic monolayers by catalytic stamp lithography: scope and limitations. ACS applied materials & interfaces\| PubMed ID: 20356148	2009
Building upon patterned organic monolayers produced via catalytic stamp lithography. ACS applied materials & interfaces\| PubMed ID: 20735101	2010
Capturing by self-assembled block copolymer thin films: transfer printing of metal nanostructures on textured surfaces. Chemical communications (Cambridge, England)\| PubMed ID: 24247179	2014

Hidenori Mizuno

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