Refractive index sensing and surface-enhanced Raman spectroscopy using silver–gold layered bimetallic plasmonic crystals

• Somi Kang,
• Sean E. Lehman,
• Matthew V. Schulmerich,
• An-Phong Le,
• Tae-woo Lee,
• Stephen K. Gray,
• Rohit Bhargava and
• Ralph G. Nuzzo

Beilstein J. Nanotechnol. 2017, 8, 2492–2503, doi:10.3762/bjnano.8.249

• slide was fully covered with liquid SOG, and spin cast (≈950 rpm for 6 s) to produce a thin, uniform layer of liquid SOG on the glass slide surface. The PDMS stamp was then pressed into the SOG-coated glass slide and fastened in place to achieve conformal contact between the PDMS stamp and SOG film

• penetration of liquid solution into the interfaces formed between the metal films and the SOG substrate. To prevent the degradation in performance that this engendered, a conformal ≈6 nm thick Al2O3 passivation film was deposited on top of the metal by atomic layer deposition (Cambridge Nanotech). Bulk

• more continuous/conformal metal layers formed by sputter deposition are termed full-3D PCs [37]. Figure 1a schematically illustrates the metal film distribution differences resulting from the fabrication using these two methods. The geometric differences in the metal films of the quasi-3D and the full

Increasing the stability of DNA nanostructure templates by atomic layer deposition of Al₂O₃ and its application in imprinting lithography

• Hyojeong Kim,
• Kristin Arbutina,
• Anqin Xu and
• Haitao Liu

Beilstein J. Nanotechnol. 2017, 8, 2363–2375, doi:10.3762/bjnano.8.236

• conformal coating with a nanometer-thin protective inorganic oxide layer created using atomic layer deposition (ALD). DNA nanotubes and origami triangles were coated with ca. 2 nm to ca. 20 nm of Al2O3. Nanoscale features of the DNA nanostructures were preserved after the ALD coating and the patterns are

• still remains a challenge to develop an approach to increase the stability of the DNA nanostructure master templates. In this paper, we establish a method to increase the chemical and/or mechanical stability of DNA nanostructure master templates by a nanometer-thin conformal coating of a protective

• indicate that there is a limit to the thickness of the protective Al2O3 film deposited by ALD to maintain the nanoscale feature of the DNA nanostructure on the template. Conclusion We have reported a method to increase the stability of DNA nanostructure master templates through the conformal growth of an

Tailoring the nanoscale morphology of HKUST-1 thin films via codeposition and seeded growth

• Landon J. Brower,
• Lauren K. Gentry,
• Amanda L. Napier and
• Mary E. Anderson

Beilstein J. Nanotechnol. 2017, 8, 2307–2314, doi:10.3762/bjnano.8.230

• porous networks; and conformal, continuous surfaces are necessary for the incorporation of the MOF within the multilayer stacks commonly implemented for device architectures. Additionally, thin nanoscale films are necessary for the incorporation of surMOFs as dielectric layers and thick microscale films

• substrates [11][12][13][14]. The growth mechanism for HKUST-1 surMOF films fabricated by LBL deposition was found to be Volmer–Weber, with small crystallites nucleating and ripening on the substrate upon continued deposition cycles, as opposed to a van der Merwe growth mechanism that produces a conformal

• investigations using seeded surMOF films formed by codeposition or LBL were effective for fabricating conformal, continuous, and thinner films from more dilute dropcast solutions. Future research will further optimize this process by controlling solution concentration, temperature, and atmospheric conditions to

Vapor-based polymers: from films to nanostructures

• Meike Koenig and
• Joerg Lahann

Beilstein J. Nanotechnol. 2017, 8, 2219–2220, doi:10.3762/bjnano.8.221

• larger polymers are used, enable the highly conformal character of vapor-based coatings. The review article by Moni et al., within this Thematic Series, highlights this feature and discusses how to assess it, as well as its applications [6]. In their research article, Cheng and Gupta present another

• exemplary application of vapor-borne coatings. Here, a 3D-printed device can be equipped with the desired functionality on its surface, while the bulk material can be chosen independently, according to the requirements of the printing process and the desired mechanical properties [7]. The conformal

• from the coating material, which, in turn, often results in superior biocompatibility [10]. This, together with the conformal character of the coating, is of importance in a novel antibacterial catheter introduced by Franz et al. [11] Here, poly(p-xylylene), which is deposited via chemical vapor

Bi-layer sandwich film for antibacterial catheters

• Gerhard Franz,
• Florian Schamberger,
• Hamideh Heidari Zare,
• Sara Felicitas Bröskamp and
• Dieter Jocham

Beilstein J. Nanotechnol. 2017, 8, 1982–2001, doi:10.3762/bjnano.8.199

• coating, because it forms the very stable complex [Ag(NH3)2]+, which dissolves a possible precipitate of AgCl [19]. 3. Among the various deposition techniques, chemical vapor deposition (CVD) is known for its outstanding conformal coatings, in particular on three-dimensional substrates. Because the

• vacuum apparatus. Chemical vapor deposition differs from physical vapor deposition by the fact that one or more substances are evaporated and undergo a chemical reaction during transport to a surface. The main advantage of CVD is conformal coating even on heavily rugged surfaces, which makes it the

• conformal. This means it needs to exhibit a certain constant porosity along the capillary, i.e., a certain and reliable thickness along the catheter, irrespective of whether the surface of the bottom layer is bent or parallel to the wall. Since the exterior wall surface of the catheter is in intimate

Surface functionalization of 3D-printed plastics via initiated chemical vapor deposition

• Christine Cheng and
• Malancha Gupta

Beilstein J. Nanotechnol. 2017, 8, 1629–1636, doi:10.3762/bjnano.8.162

• , allowing for conformal coating on complex surfaces such as mictrotrenches [25] and nanopore membranes [26]. Since the rate of reaction in iCVD is limited by adsorption of monomer to the substrate, a lower substrate temperature results in a faster polymerization rate [24]. Thus, the thermally insulating

Parylene C as a versatile dielectric material for organic field-effect transistors

• Tomasz Marszalek,
• Maciej Gazicki-Lipman and
• Jacek Ulanski

Beilstein J. Nanotechnol. 2017, 8, 1532–1545, doi:10.3762/bjnano.8.155

• under the commercial name of parylenes, is unique in many ways. It is a synthetic path for polymer formation, at the same time it belongs to the category of chemical vapor deposition (CVD) and, as such, it yields products in a form of conformal solid films depositing at any surface exposed. As a CVD

• with the accompanying chemical reactions, is presented in Figure 1. There is a number of advantages of the parylene technology. First of all, being a gas-phase diffusion-controlled process, it yields smooth pinhole-free conformal coatings with excellent penetration abilities. Second, there are several

• . Parylene C forms transparent, pinhole-free conformal coatings of thicknesses as low as 0.1 μm with excellent dielectric and mechanical properties. Increasing thickness to 0.2 mm suffices to uniformly cover rough colloidal-graphite contacts. Transistors with rubrene as semiconductor and parylene as

Micro- and nano-surface structures based on vapor-deposited polymers

• Hsien-Yeh Chen

Beilstein J. Nanotechnol. 2017, 8, 1366–1374, doi:10.3762/bjnano.8.138

• the resulting coatings are mostly applicable to a wide range of substrate materials [1]. In addition, the vapor deposition process typically provides excellent coating fidelity, i.e., the resulting polymer coatings are conformal with respect to micrometer- or nanometer-sized topology of the substrate

• polymerization/deposition has the advantage of conformal coverage of substrates, the vapor-phase polymers are freely accessible to deposit on micro- and nano-structured surfaces, curved surfaces, confined microfluidic channels, 3D structures, and substrates with complex geometry [3][31][32]. Although an

Oxidative chemical vapor deposition of polyaniline thin films

• Yuriy Y. Smolin,
• Masoud Soroush and
• Kenneth K. S. Lau

Beilstein J. Nanotechnol. 2017, 8, 1266–1276, doi:10.3762/bjnano.8.128

• advantageous route for depositing conducting polymer thin films without the need of a solvent or a conductive substrate, which naturally makes the process amenable in a wide range of applications [17][21]. Other methods such as plasma-enhanced CVD (PECVD) have previously been used to make conformal and uniform

• morphology were highly dependent on the solvent matrix and the laser irradiation wavelength, and MAPLE led to a film that was electrically insulating [26]. Previous studies by Gleason and coworkers highlighted oCVD’s advantages in the conformal deposition of PEDOT films with tunable nanoporosity [27], and

• utility of oCVD in the synthesis of PTh and showed that the polymer conjugation length and electrical conductivity can be tuned by adjusting the oCVD processing conditions [31]. We further deposited ultrathin (4–6 nm) conformal and uniform PTh coatings within porous nanostructures, including anodized

Nanotopographical control of surfaces using chemical vapor deposition processes

• Meike Koenig and
• Joerg Lahann

Beilstein J. Nanotechnol. 2017, 8, 1250–1256, doi:10.3762/bjnano.8.126

• interfere with the structuring process. In addition, the process can be applied on thermo- or chemically sensitive substrates and can be used to deposit insoluble polymers. The use of vaporized monomers rather than polymer solutions ensures the conformal coating of the substrate and masks, where required

A top-down approach for fabricating three-dimensional closed hollow nanostructures with permeable thin metal walls

• Carlos Angulo Barrios and
• Víctor Canalejas-Tejero

Beilstein J. Nanotechnol. 2017, 8, 1231–1237, doi:10.3762/bjnano.8.124

• could be considered to form the nanocages. For example, sputtering could be used to create nanometer-thick amorphous or polycrystalline films, which are expected to have pores (voids) and diffusion paths (grain boundaries). Note, however, that the sputtering technique typically leads to highly conformal

Synthesis of coaxial nanotubes of polyaniline and poly(hydroxyethyl methacrylate) by oxidative/initiated chemical vapor deposition

• Alper Balkan,
• Efe Armagan and
• Gozde Ozaydin Ince

Beilstein J. Nanotechnol. 2017, 8, 872–882, doi:10.3762/bjnano.8.89

• applications in light emitting diodes [15], photovoltaic cells [16][17], supercapacitors [18], sensors [19] and drug delivery [20]. During synthesis of these nanostructures, the use of solvents is a major drawback for homogeneity and conformal coatings, especially on high-aspect-ratio templates, due to wetting

• effect and surface tension. Thus, vapor-phase polymerization techniques have emerged for the deposition of conducting polymers that facilitate the fabrication of conformal polymeric structures [21][22]. Polyaniline (PANI) is one of the well-known conducting polymers with applications in supercapacitors

• were done via oxidative chemical vapor deposition (oCVD) and initiated chemical vapor deposition (iCVD) to enhance the control and sensitivity level of humidity sensors. By using the vapor deposition method oCVD, we achieved conformal coatings of PANI, which allowed us to produce nanotubes with high

Vapor deposition routes to conformal polymer thin films

• Priya Moni,
• Ahmed Al-Obeidi and
• Karen K. Gleason

Beilstein J. Nanotechnol. 2017, 8, 723–735, doi:10.3762/bjnano.8.76

• , USA 10.3762/bjnano.8.76 Abstract Vapor phase syntheses, including parylene chemical vapor deposition (CVD) and initiated CVD, enable the deposition of conformal polymer thin films to benefit a diverse array of applications. This short review for nanotechnologists, including those new to vapor

• deposition methods, covers the basic theory in designing a conformal polymer film vapor deposition, sample preparation and imaging techniques to assess film conformality, and several applications that have benefited from vapor deposited, conformal polymer thin films. Keywords: conformal; polymers; thin

• films; vapor deposition; Review Introduction Conformal coverage is achieved when a film of uniform thickness precisely follows the geometry of the underlying substrate. Conformal coatings allow for surface properties to be optimized independently from the choice of the bulk material and shape of the

Advances in the fabrication of graphene transistors on flexible substrates

• Gabriele Fisichella,
• Stella Lo Verso,
• Silvestra Di Marco,
• Vincenzo Vinciguerra,
• Emanuela Schilirò,
• Salvatore Di Franco,
• Raffaella Lo Nigro,
• Fabrizio Roccaforte,
• Amaia Zurutuza,
• Alba Centeno,
• Sebastiano Ravesi and
• Filippo Giannazzo

Beilstein J. Nanotechnol. 2017, 8, 467–474, doi:10.3762/bjnano.8.50

• layer deposition (ALD) represents an optimal method to fabricate a good quality Al2O3 dielectric film with a tight control on the deposited thickness and a high level of conformal coverage. While the thickness control allows easy fabrication of a tens of nanometer thick dielectric film (resulting in a

• beneficially high dielectric capacitance), the conformal coverage is essential to contain the potential local degradation of the dielectric performance. Otherwise, this degradation can take over due to the device topography and the high starting roughness of the plastic substrate. ALD is essentially a low

Phosphorus-doped silicon nanorod anodes for high power lithium-ion batteries

• Chao Yan,
• Qianru Liu,
• Jianzhi Gao,
• Zhibo Yang and
• Deyan He

Beilstein J. Nanotechnol. 2017, 8, 222–228, doi:10.3762/bjnano.8.24

• both of Cu(OH)2 and CuO nanorods, which was about 150 nm. The morphology of the obtained Si anode is illustrated in Figure 5c. The Si anode inherited the nanorod structure of the CuO precursor and presented a conformal Si coating. Comparing the insets in Figure 5b and Figure 5c, it can be estimated

Diffusion of dilute gas in arrays of randomly distributed, vertically aligned, high-aspect-ratio cylinders

• Wojciech Szmyt,
• Carlos Guerra and
• Ivo Utke

Beilstein J. Nanotechnol. 2017, 8, 64–73, doi:10.3762/bjnano.8.7

• ][26], as well as for ALD growth in nanopores [27][28][29][30][31], and conformal CVD [32] considering kinetic parameters of surface sticking, surface diffusion, adsorption and desorption phenomena as a function of gas pressure and temperature. Recently Arya et al. [33][34] suggested that for

Sb₂S₃ grown by ultrasonic spray pyrolysis and its application in a hybrid solar cell

• Erki Kärber,
• Atanas Katerski,
• Ilona Oja Acik,
• Arvo Mere,
• Valdek Mikli and
• Malle Krunks

Beilstein J. Nanotechnol. 2016, 7, 1662–1673, doi:10.3762/bjnano.7.158

• mesoporous TiO2 as the electron conductor, or when compared to a planar cell based on ALD-grown Sb2S3 [5]. The latter corroborates the benefit of a conformal coating and controlled thickness that is characteristic for ALD. As we have previously shown, the use of ZnO nanorods as the structured substrate and

• from planar to nanostructured. In either configuration, flat or structured, the Sb2S3 is expected to be a continuous absorber layer. Such a further development, a conformal Sb2S3 layer deposited by ultrasonic spray on top of a nanostructured electron conducting substrate, is presently in progress

Development of highly faceted reduced graphene oxide-coated copper oxide and copper nanoparticles on a copper foil surface

• Rebeca Ortega-Amaya,
• Yasuhiro Matsumoto,
• Andrés M. Espinoza-Rivas,
• Manuel A. Pérez-Guzmán and
• Mauricio Ortega-López

Beilstein J. Nanotechnol. 2016, 7, 1010–1017, doi:10.3762/bjnano.7.93

• the formation of a well-closed conformal coating at the CuNP surface. This might explain the stability against oxidation observed in these particles. In regarding to dominant phase, we propose that Cu2O reacts with gaseous carbonaceous species derived from the GO reduction process to become Cu, this

Hydration of magnesia cubes: a helium ion microscopy study

• Ruth Schwaiger,
• Johannes Schneider,
• Gilles R. Bourret and
• Oliver Diwald

Beilstein J. Nanotechnol. 2016, 7, 302–309, doi:10.3762/bjnano.7.28

• Information File 1). The sample position characterized by the image in Figure 5 shows larger MgO cubes before (Figure 5a) and after 17 h of exposure to liquid water (Figure 5b). In that case the material exhibits the morphological changes discussed above, i.e., the evolution of a conformal hydroxide layer on

Electrochemical coating of dental implants with anodic porous titania for enhanced osteointegration

• Amirreza Shayganpour,
• Alberto Rebaudi,
• Pierpaolo Cortella,
• Alberto Diaspro and
• Marco Salerno

Beilstein J. Nanotechnol. 2015, 6, 2183–2192, doi:10.3762/bjnano.6.224

• anodic porous titania can be obtained not only on ultrapure and flat titanium but also as a conformal coating on curved surfaces of real objects made of industrial titanium alloys. Raman spectroscopy showed that the titania phase obtained is anatase. Furthermore, it was demonstrated that by carrying out

• Anodization in acid electrolyte provides a conformal coating with pores also formed on curved surfaces of commercial grade Ti, and is thus a feasible approach for the nanopatterning of dental implant surfaces. The implants of the same Ti grade from the two different companies considered here did not present

Surface engineering of nanoporous substrate for solid oxide fuel cells with atomic layer-deposited electrolyte

• Sanghoon Ji,
• Waqas Hassan Tanveer,
• Wonjong Yu,
• Sungmin Kang,
• Gu Young Cho,
• Sung Han Kim,
• Jihwan An and
• Suk Won Cha

Beilstein J. Nanotechnol. 2015, 6, 1805–1810, doi:10.3762/bjnano.6.184

• pinhole issues causing gas permeation and electrode diffusion due to the rough surface of porous substrates [5]. This drawback necessitates conformal and dense thin film electrolytes, and can appreciably be relieved with an aid of atomic layer deposition (ALD) technique that is governed by binary reaction

• generates high open circuit voltages (OCVs) of ≈1.17 V implying the high integrity of conformal and dense YSZ electrolytes, which is quite contiguous to the theoretical OCV value of 1.18 V under the operating conditions [12]. However, the overall voltage drop of the Cell-A with increasing current density is

• infiltrates into the interior of the BEC as well as into AAO pores (the left image of Figure 2A), which may have negative impacts on fuel supply through AAO pores. In case of the thicker BEC, on the other hand, most of the conformal YSZ is deposited on the top surface of the BEC, as shown in the right image

Simple approach for the fabrication of PEDOT-coated Si nanowires

• Mingxuan Zhu,
• Marielle Eyraud,
• Judikael Le Rouzo,
• Nadia Ait Ahmed,
• Florence Boulc’h,
• Claude Alfonso,
• Philippe Knauth and
• François Flory

Beilstein J. Nanotechnol. 2015, 6, 640–650, doi:10.3762/bjnano.6.65

• Matériaux, 13397 Marseille Cedex 20, France, Université Abderrahmane Mira, Lab. d’Electrochimie, Corrosion et de Valorisation énergétique, 06000 Bejaia, Algeria 10.3762/bjnano.6.65 Abstract The synthesis of a conformal poly(3,4-ethylenedioxythiophene) (PEDOT) layer on Si nanowires was demonstrated using a

• electrochemical methods. Since the polymerization reaction is a very fast process with regards to monomer diffusion along the SiNW, the conformal deposition by classical, fixed potential deposition was not favored. Instead, the core–shell heterojunction structure was finally achieved by a pulsed deposition method

• surface uncovered [16]. In order to improve the junction quality, a conformal PEDOT shell should be introduced to eliminate charge transport paths parallel to the diode. Compared with the spin coating technique, the electrochemical polymerization of PEDOT provides the possibility of excellent polymer

Entropy effects in the collective dynamic behavior of alkyl monolayers tethered to Si(111)

• Christian Godet

Beilstein J. Nanotechnol. 2015, 6, 583–594, doi:10.3762/bjnano.6.60

• relaxation peak intensities, relaxation mechanisms B1 and B2 will be, respectively, attributed to acid end-group dipoles and to gauche defect configurations. Results As reported previously [32], several techniques were used to obtain complementary information on the conformal coverage (STM, AFM), OML

Synergic combination of the sol–gel method with dip coating for plasmonic devices

• Cristiana Figus,
• Maddalena Patrini,
• Francesco Floris,
• Lucia Fornasari,
• Paola Pellacani,
• Gerardo Marchesini,
• Andrea Valsesia,
• Flavia Artizzu,
• Daniela Marongiu,
• Michele Saba,
• Franco Marabelli,
• Andrea Mura,
• Giovanni Bongiovanni and
• Francesco Quochi

Beilstein J. Nanotechnol. 2015, 6, 500–507, doi:10.3762/bjnano.6.52

• the silica layer thickness on a plasmonic structure were studied in this work. The plasmonic nanostructures were coated with conformal silica layers of controlled thickness using an optimized, combined sol–gel/dip-coating technique. The effects of the silica layer on the optical properties of the

• first layer). Conformal silica layers (i.e., those which maintain the original shape of the nanostructured surface) with a homogeneous coating was achieved, as is evidenced by the AFM topography after coating (Figure 5). The AFM images of the surface reported in Figure 5 show the topography and the 3D

Conformal SiO₂ coating of sub-100 nm diameter channels of polycarbonate etched ion-track channels by atomic layer deposition

• Nicolas Sobel,
• Christian Hess,
• Manuela Lukas,
• Anne Spende,
• Bernd Stühn,
• M. E. Toimil-Molares and
• Christina Trautmann

Beilstein J. Nanotechnol. 2015, 6, 472–479, doi:10.3762/bjnano.6.48

• membranes by small angle X-ray scattering (SAXS) reveals a homogeneous, conformal layer of SiO2 in the channels at a deposition rate of 1.7–1.8 Å per ALD cycle. Characterization by infrared and X-ray photoelectron spectroscopy (XPS) confirms the stoichiometric composition of the SiO2 films. Detailed XPS

• properties such as diameter and conformation variations due to dangling bonds, swelling, or surface charge variations from pH changes of the solution, are to a large extent unknown but can influence ion transport and the control of surface modification steps in a crucial manner. A homogeneous conformal

• surfaces, one must guarantee the thermal stability of the polymer. We thus developed a low-temperature process by using silicon tetrachloride (SiCl4) and water as precursors and pyridine as catalyst. For PC track-etched membranes this approach successfully produces uniform and conformal SiO2 coatings. To