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Transparent conducting electrodes (TCEs) are essential components in various optoelectronic devices. Nanostructured metallic thin film is one of the promising candidates to complement current metal oxide films, such as ITO, where high cost rare earth elements have been a longstanding issue. Herein, we present that multiscale porous metal nanomesh thin films prepared by bimodal self-assembly of block copolymer (BCP)/homopolymer blends may offer a new opportunity for TCE. This hierarchical concurrent self-assembly consists of macrophase separation between BCP and homopolymer as well as microphase separation of BCP, and thus provides a straightforward spontaneous production of a highly porous multiscale pattern over an arbitrary large area. Employing a conventional pattern transfer process, we successfully demonstrated a multiscale highly porous metallic thin film with reasonable optical transparency, electro-conductance, and large-area uniformity, taking advantage of low loss light penetration through microscale pores and significant suppression of light reflection at the nanoporous structures. This well-defined controllable bimodal self-assembly can offer valuable opportunities for many different applications, including optoelectronics, energy harvesting, and membranes.

A facile direct hybridization route to prepare SnO2/graphene nanocomposites for Li-ion battery anode application is demonstrated. Uniform distribution of SnO2 nanoparticles on graphene layers was enabled by a one-step chemical synthetic route. The optimal content ratio of SnO2 and graphene was determined from microscopic observations and electrochemical studies. The nanocomposite anode with SnO2 loading level of around 70 wt.% retained reversible capacity of 643.6 mAh/g after 50 cycles and high discharge capacity of 347.8 mAh/g at a current density of 3000 mA/g, which was superior to that of graphene-only electrodes or nanocomposites with overloaded SnO2 nanoparticles. Taking advantage of nano-sized SnO2 and an electrically conductive and mechanically flexible graphene layer, SnO2/graphene nanocomposites with optimized SnO2 content exhibit excellent electrochemical properties as lithium-ion battery anodes. Our strategy offers a straightforward and high-throughput pathway for creating and directing graphene-based functional hybrids through simple mixing and thermal treatments, and may be used to assemble high-performance Li-ion batteries.

thus far.Here we demonstrate that chemically modified grapheneis an excellent substrate material for adsorption and also forspatial patterning of DNA origami structures. Our strategy isto integrate the top-down patterning of chemically modifiedgraphene through conventional photolithography withbottom-up self-assembly of DNA origami structures uponthe patterned chemically modified graphene. Because of thesmoothness at atomic scale and chemical diversity of chemi-cally modified graphene, including GO, reduced grapheneoxide (rGO), and nitrogen-doped reduced graphene oxide(NrGO), the adsorption of DNA origami structures can besystematically tuned to allow spatial patterning on chemicallymodified graphene.Figure 1 illustrates the procedure for patterning of DNAorigami structures. A GO film was spin-cast from aqueoussolution onto an NH

solar cells, [ 4 ] and photonic crystals, [ 5 ] 2D hexagonal structures and 3D inverted opal (IO) structures have recently been intensively studied. In order to fabricate uniform IO structures consisting of regular arrangements of spherical void spaces surrounded by solid walls, 2D and 3D colloidal crystals consisting of a regular arrangement of uniform spherical particles are required. To date, a number of techniques to assemble colloidal particles into 2D and 3D opals have been developed: 3D colloidal crystals have been fabricated by sedimentation, [ 6 ] convective assembly, [ 7 ] and electrophoretic deposition, [ 8 ] while 2D colloidal crystals are produced by confi ned convective assembly. [ 9 ] Generally, 2D colloidal crystals have been used to fabricate 2D structures through edge spreading lithography, [ 10 ] colloidal masking, and templating while 3D colloidal crystals have been independently utilized to construct 3D structures through infi ltration and templating. [ 11 , 12 ]

The fabrication and catalytic application of a size-tunable monodisperse nanoparticle array enabled by block copolymer lithography is demonstrated. Highly uniform vertical cylinder nanodomains are achieved in poly(styrene-block-4-vinylpyridine) (PS-b-P4VP) diblock copolymer thin-films by solvent annealing. The prominent diffusion of the anionic metal complexes into the protonated P4VP cylinder nanodomains occurs through specific electrostatic interactions in a weakly acidic aqueous solution. This well-defined diffusion with nanoscale confinement enables preparation of the laterally ordered monodisperse nanoparticle array with sub-nanometer level precise size tuning. The controlled growth of monodisperse nanoparticle arrays is proven by their catalytic use for vertical carbon nanotube (CNT) growth via plasma enhanced chemical vapor deposition (PECVD). Since the size of the catalyst particles is the decisive parameter for the diameters and wall-numbers of CNTs, the highly selective growth of double-walled or triple-walled CNTs could be accomplished using monodisperse nanoparticle arrays.

We present block copolymer multiple patterning as an efficient and truly scalable nanolithography for sub-20 nm scale patterning, synergistically integrated with conventional ArF lithography. The directed assembly of block copolymers on chemically patterned substrates prepared by ArF lithography generated linear vertical cylinder arrays with a 20 to 30 nm diameter, enhancing the pattern density of the underlying chemical patterns by a factor of two or three. This self-assembled resolution enhancement technique affords a straightforward route to highly ordered sub-20 nm scale features via conventional lithography.

A symmetric block copolymer was spontaneously assembled into a laterally stacked, one-dimensional lamellar assembly along the chemically stripe patterned surfaces. The lateral dimension of the line...

This work was supported by the Center for Electronic Packaging Materials (ERC) of MOST/KOSEF (R11-2000-085-08 004-0), the second stage of the Brain Korea 21 Project, the Korea Government (MOEHRD) (KRF-2005-003-D00 085), the Korea Science & Engineering Foundation (R01-2005-000-10 456-0), the Korean Ministry of Science and Technology, and the Fundamental R&D Program for Core Technology of Materials funded by the Ministry of Commerce, Industry, and Energy, Republic of Korea.

We thank Sung Soon Bai for providing technical support for SEM characterization. This work was supported by the Samsung Advanced Institute of Technology (SAIT), the Korea Research Foundation (KRF-2005-003-D00085), the second stage of the Brain Korea 21 Project, the Korea Science & Engineering Foundation (KOSEF) (R01-2005-000-10456-0), the Korean Ministry of Science and Technology, and the Fundamental R&D Program for Core Technology of Materials funded by the Korean Ministry of Commerce, Industry and Energy. Supporting Information is available online from Wiley InterScience or from the author.

We thank G. S. Kim and J.-H. Ahn for assistance with thin film depositions, and S. S. Bae for assistance with SEM analysis. This work was supported by the second stage of the Brain Korea 21 Project, the Korea Research Foundation (KRF-2005-003-D00085), the Basic Research Program of the Korea Science & Engineering Foundation (R01-2005- 000-10456-0), the Korean Ministry of Science and Technology, and the Korean Ministry of Science and Technology and Fundamental R&D Program for Core Technology of Materials funded by the Korean Ministry of Commerce, Industry and Energy. Also, this work was partially supported by grants-in-aid for the National Core Research Center Program from MOST/KOSEF (No. R15-2006-022-01001-0).

The experimental portion of this research was performed in the laboratories of Prof. Paul F. Nealey at the University of Wisconsin. The authors thank National Nanofab Center (NNFC) in Korea for technical support for characterization. This work was supported by the second stage of the Brain Korea 21 Project, the Basic Research Program of the Korea Science & Engineering Foundation (R01-2005- 000-10456-0), and Colorado State University. Supporting Information is available online from Wiley InterScience or from the authors.

Nanoscale alloys attract enormous research attentions in catalysis, magnetics, plasmonics and so on. Along with multicomponent synergy, quantum confinement and extreme large surface area of nanoalloys offer novel material properties, precisely and broadly tunable with chemical composition and nanoscale dimension. Despite substantial progress of nanoalloy synthesis, the randomized positional arrangement and dimensional/compositional inhomogeneity of nanoalloys remain significant technological challenges for advanced applications. Here we present a generalized route to synthesize single-crystalline intermetallic nanoalloy arrays with dimensional and compositional uniformity via self-assembly. Specific electrostatic association of multiple ionic metal complexes within self-assembled nanodomains of block copolymers generated patterned monodisperse bimetallic/trimetallic nanoalloy arrays consisting of various elements, including Au, Co, Fe, Pd, and Pt. The precise controllability of size, composition, and intermetallic crystalline structure of nanoalloys facilitated tailored synergistic properties, such as accelerated catalytic growth of vertical carbon nanotubes from Fe-Co nanoalloy arrays.

Complex nanopatterns integrating diverse nanocomponents are crucial requirements for advanced photonics and electronics. Currently, such multicomponent nanopatterns are principally created by colloidal nanoparticle assembly, where large-area processing of highly ordered nanostructures raises significant challenge. We present multicomponent nanopatterns enabled by block copolymer (BCP) self-assembly, which offers device oriented sub-10-nm scale nanopatterns with arbitrary large-area scalability. In this approach, BCP nanopatterns direct the nanoscale lateral ordering of the overlaid second level BCP nanopatterns to create the superimposed multicomponent nanopatterns incorporating nanowires and nanodots. This approach introduces diverse chemical composition of metallic elements including Au, Pt, Fe, Pd, and Co into sub-10-nm scale nanopatterns. As immediate applications of multicomponent nanopatterns, we demonstrate multilevel charge-trap memory device with Pt-Au binary nanodot pattern and synergistic plasmonic properties of Au nanowire-Pt nanodot pattern.

Mushroom-shaped phase change memory (PCM) consisting of a Cr/In(3)Sb(1)Te(2) (IST)/TiN (bottom electrode) nanoarray was fabricated via block copolymer lithography and single-step dry etching with a gas mixture of Ar/Cl(2). The process was performed on a high performance transparent glass-fabric reinforced composite film (GFR Hybrimer) suitable for use as a novel substrate for flexible devices. The use of GFR Hybrimer with low thermal expansion and flat surfaces enabled successful nanoscale patterning of functional phase change materials on flexible substrates. Block copolymer lithography employing asymmetrical block copolymer blends with hexagonal cylindrical self-assembled morphologies resulted in the creation of hexagonal nanoscale PCM cell arrays with an areal density of approximately 176 Gb/in(2).

Mussel-inspired interfacial engineering is synergistically integrated with block copolymer (BCP) lithography for the surface nanopatterning of low surface energy substrate materials, including, Teflon, graphene, and gold. The image shows the Teflon nanowires and their excellent superhydrophobicity.

A highly efficient, ultralarge-area nanolithography that integrates block-copolymer lithography with single-step ZnO nanoimprinting is introduced. The UV-assisted imprinting of a photosensitive sol-gel precursor creates large-area ZnO topographic patterns with various pattern shapes in a single-step process. This straightforward approach provides a smooth line edge and high thermal stability of the imprinted ZnO pattern; these properties are greatly advantageous for further graphoepitaxial block-copolymer assembly. According to the ZnO pattern shape and depth, the orientation and lateral ordering of self-assembled cylindrical nanodomains in block-copolymer thin films could be directed in a variety of ways. Significantly, the subtle tunability of ZnO trench depth enabled by nanoimprinting, generated complex hierarchical nanopatterns, where surface-parallel and surface-perpendicular nanocylinder arrays are alternately arranged. The stability of this complex morphology is confirmed by self-consistent field theory (SCFT) calculations. The highly ordered graphoepitaxial nanoscale assembly achieved on transparent semiconducting ZnO substrates offers enormous potential for photonics and optoelectronics.

We demonstrate a surface energy modification method exploiting graphene film. Spin-cast, atomic layer thick, large-area reduced graphene film successfully played the role of surface energy modifier for arbitrary surfaces. The degree of reduction enabled the tuning of the surface energy. Sufficiently reduced graphene served as a neutral surface modifier to induce surface perpendicular lamellae or cylinders in a block copolymer nanotemplate. Our approach integrating large-area graphene film preparation with block copolymer lithography is potentially advantageous in creating semiconducting graphene nanoribbons and nanoporous graphene.

We accomplished a facile and scalable route to linearly stacked, one-dimensional metal nanowire assembly via soft graphoepitaxy of block copolymers. A one-dimensional nanoscale lamellar stack could be achieved by controlling the block copolymer film thickness self-assembled within the disposable topographic confinement and utilized as a template to generate linear metal nanowire assembly. The mechanism underlying this interesting morhpology evolution was investigated by self-consistent field theory. The optical properties of metal nanowire assembly involved with surface plasmon polariton were investigated by first principle calculations.

Highly uniform vertical carbon nanotube arrays were prepared by a novel hybrid approach combining a plasma-enhanced chemical vapor deposition (PECVD) process with self-assembled block copolymer nanotemplate. Monodisperse catalyst nanoparticles were prepared on a substrate using self-assembled nanoporous block copolymer templates. The subsequent PECVD growth of vertical CNTs from the nanopatterned catalyst particles provided highly oriented vertical CNT arrays, which are potentially useful for device integration of CNTs.

We present a large-area, highly aligned lamellar block copolymer self-assembly directed by graphoepitaxially aligned cylinder block copolymer self-assembly. Asymmetric block copolymer thin films were graphoepitaxially assembled within 1 μm wide parallel photoresist trenches to generate surface-parallel nanocylinder arrays. After the graphoepitaxial morphology was frozen by a radiative treatment, a thin film of symmetric block copolymer was deposited over the nanocylinder array, where the lamellar period was consistent with the period of the underlying cylinder array. Subsequent thermal annealing generated highly aligned lamellar morphology over a large area without any trace of an underlying photoresist pattern. Our method employing surface-parallel cylinder self-assembly as a structure-directing chemical pattern for epitaxial self-assembly does not require any substrate surface pretreatment and is, thus, highly efficient for nanopatterning various substrates.

The fabrication and catalytic application of a size-tunable monodisperse nanoparticle array enabled by block copolymer lithography is demonstrated. Highly uniform vertical cylinder nanodomains are achieved in poly(styrene-block-4-vinylpyridine) (PS-b-P4VP) diblock copolymer thin-films by solvent annealing. The prominent diffusion of the anionic metal complexes into the protonated P4VP cylinder nanodomains occurs through specific electrostatic interactions in a weakly acidic aqueous solution. This well-defined diffusion with nanoscale confinement enables preparation of the laterally ordered monodisperse nanoparticle array with sub-nanometer level precise size tuning. The controlled growth of monodisperse nanoparticle arrays is proven by their catalytic use for vertical carbon nanotube (CNT) growth via plasma enhanced chemical vapor deposition (PECVD). Since the size of the catalyst particles is the decisive parameter for the diameters and wall-numbers of CNTs, the highly selective growth of double-walled or triple-walled CNTs could be accomplished using monodisperse nanoparticle arrays.

Highly uniform and dense, hexagonal noble metal nanoparticle arrays were achieved on large-area transparent glass substrates via scalable, parallel processing of block copolymer lithography. Exploring their localized surface plasmon resonance (LSPR) characteristics revealed that the Ag nanoparticle array displayed a UV-vis absorbance spectrum sufficiently narrow and intense for biosensing application. A highly-sensitive, label-free detection of prostate cancer specific antibody (anti-PSA) with sub-ng ml−1 level detection limit (0.1∼1 ng ml−1) has been accomplished with the plasmonic nanostructure. Our approach offers a valuable route to a low-cost, manufacture-scale production of plasmonic nanostructures, potentially useful for various photonic and optoelectronic devices.