Disorder in H⁺-irradiated HOPG: effect of impinging energy and dose on Raman D-band splitting and surface topography

• Lisandro Venosta,
• Noelia Bajales,
• Sergio Suárez and
• Paula G. Bercoff

Beilstein J. Nanotechnol. 2018, 9, 2708–2717, doi:10.3762/bjnano.9.253

• structural disorder from hydrogenation is not possible, because the cross section of C–C sp3 bonds in visible Raman characterization is negligible [9][18][21]. Besides, the observed shapes of the ID/IG ratio and the G band are consistent with those corresponding to graphite-like hydrogenated amorphous carbon

• et al. [15] investigated the multi-wavelength Raman spectra of a variety of hydrogenated amorphous carbon materials, which allowed them to estimate values for their bond structure, hydrogen content and mechanical properties. A remarkable conclusion is that UV Raman spectroscopy allows for the

Impact of the anodization time on the photocatalytic activity of TiO₂ nanotubes

• Jesús A. Díaz-Real,
• Geyla C. Dubed-Bandomo,
• Juan Galindo-de-la-Rosa,
• Luis G. Arriaga,
• Janet Ledesma-García and
• Nicolas Alonso-Vante

Beilstein J. Nanotechnol. 2018, 9, 2628–2643, doi:10.3762/bjnano.9.244

• along the length and the wall thickness of the TNTs due to etching during the growth process. In his work, he chose f = 3 Hz to avoid interferences from the double-layer capacitance. Considering the amorphous-semiconductor theory [78] in the interpretation of the M–S plots of Di Quarto et al. [79], the

Pattern generation for direct-write three-dimensional nanoscale structures via focused electron beam induced deposition

• Lukas Keller and
• Michael Huth

Beilstein J. Nanotechnol. 2018, 9, 2581–2598, doi:10.3762/bjnano.9.240

• ] but also various oxides and carbides in either amorphous or polycrystalline form [18][19] are accessible. By employing additional postdeposition treatments the metal volume content of some otherwise granular metals can be increased to virtually 100% [20][21][22]. Despite the apparent simplicity of the

Exploring the photoleakage current and photoinduced negative bias instability in amorphous InGaZnO thin-film transistors with various active layer thicknesses

• Dapeng Wang and
• Mamoru Furuta

Beilstein J. Nanotechnol. 2018, 9, 2573–2580, doi:10.3762/bjnano.9.239

• and illumination stress (NBIS)-induced instability in amorphous InGaZnO thin-film transistors (a-IGZO TFTs) with various active layer thicknesses (TIGZO) were investigated. The photoleakage current was found to gradually increase in a-IGZO TFTs irrespective of the TIGZO when the photon energy of

• . Keywords: active layer thickness; gate bias; illumination stress; InGaZnO; photoleakage current; thin-film transistors; Introduction Over the last decade, the amorphous oxide-based semiconductor thin-film transistors (AOS TFTs) have attracted global attention for use in advanced display technologies due

Nanocellulose: Recent advances and its prospects in environmental remediation

• Katrina Pui Yee Shak,
• Yean Ling Pang and
• Shee Keat Mah

Beilstein J. Nanotechnol. 2018, 9, 2479–2498, doi:10.3762/bjnano.9.232

• with CNF, such as nanofibrillated cellulose (NFC), nanofibrillar cellulose, nanofibrous cellulose, and bacterial nanocellulose (BC) [24][29][30]. CNFs can be distinguished through their structure which is comprised of stretched masses of elementary nanofibrils with alternating crystalline and amorphous

• due to its higher crystallinity (Figure 2b). This is because CNCs have an elongated rod-like shape made up of crystalline regions isolated from CNFs [24]. Its assembly occurs through a series of alterations, beginning with the excision of amorphous regions in CNFs to isolate the crystalline regions

• common technique used to extract CNC from cellulose. Unlike mechanical disintegration, this technique destroys the amorphous region (non-crystalline region) in microfibrils, leaving the crystalline regions intact. Liu et al. [76] have demonstrated that CNC obtained through sulphuric acid hydrolysis (with

ZnO-nanostructure-based electrochemical sensor: Effect of nanostructure morphology on the sensing of heavy metal ions

• Marina Krasovska,
• Vjaceslavs Gerbreders,
• Irena Mihailova,
• Andrejs Ogurcovs,
• Eriks Sledevskis,
• Andrejs Gerbreders and
• Pavels Sarajevs

Beilstein J. Nanotechnol. 2018, 9, 2421–2431, doi:10.3762/bjnano.9.227

• along the (002) plane, whereas the intensity of all the remaining peaks is negligible, confirming that the ZnO nanostructure arrays are well-aligned and have a strong preferential orientation in the (002) plane direction (Figure 3). Low levels of amorphous background reveal that the nanostructures have

• forms well-developed crystallites of lead oxides mixture, whereas Cd(NO3)2 forms a very thin amorphous layer on the ZnO surface. The SEM images were recorded using secondary electrons, whose output depth is within the range of 1–10 nm; the fact that the contours of the ZnO nanotubes (bright points) are

Hydrothermal-derived carbon as a stabilizing matrix for improved cycling performance of silicon-based anodes for lithium-ion full cells

• Mirco Ruttert,
• Florian Holtstiege,
• Jessica Hüsker,
• Markus Börner,
• Martin Winter and
• Tobias Placke

Beilstein J. Nanotechnol. 2018, 9, 2381–2395, doi:10.3762/bjnano.9.223

• 46, 48149 Münster, Germany 10.3762/bjnano.9.223 Abstract In this work, silicon/carbon composites are synthesized by forming an amorphous carbon matrix around silicon nanoparticles (Si-NPs) in a hydrothermal process. The intention of this material design is to combine the beneficial properties of

• synthesized composites show a strong improvement in long-term cycling performance (capacity retention after 103 cycles: ≈55% (20 wt % Si composite) and ≈75% (10 wt % Si composite)), indicating that a homogeneous embedding of Si into the amorphous carbon matrix has a highly beneficial effect. The most

• composites (Si/C), dealing with the incorporation of Si into a variety of different carbon materials, such as graphite, graphene sheets [46][47], porous carbon structures [37][38][48] or the coating of Si using different precursors as carbon sources [49][50][51]. One simple method to form amorphous carbon

High-throughput micro-nanostructuring by microdroplet inkjet printing

• Hendrikje R. Neumann and
• Christine Selhuber-Unkel

Beilstein J. Nanotechnol. 2018, 9, 2372–2380, doi:10.3762/bjnano.9.222

• machine to 10 µm, but varies depending on the substrate material (see Figure 2 and Figure 3A–E), based on the interaction between fluid and substrate. As a consequence, poly-Si and both of the amorphous silicon (a-Si 200 and a-Si 400) samples have a droplet diameter size in the range of 76 to 84 µm, while

• the mean value of the diameter is nearly the same as the median. Amorphous silicon results in a less symmetric diameter distribution: while 50% of the droplet diameters are within the upper and lower quartiles on a-Si 400 sample and vary around 83 µm, droplet diameters on a-Si 200 sample are slightly

• voltage were optimized iteratively for each substrate between 6–12 kHz and 16–20 V. A pattern of 4 × 4 droplets with a set droplet diameter of 10 µm was printed on the following substrates: poly-silicon, amorphous silicon of 200 nm thickness (prepared by Fraunhofer ISIT, Itzehoe), amorphous silicon of 400

Performance analysis of rigorous coupled-wave analysis and its integration in a coupled modeling approach for optical simulation of complete heterojunction silicon solar cells

• Ziga Lokar,
• Benjamin Lipovsek,
• Marko Topic and
• Janez Krc

Beilstein J. Nanotechnol. 2018, 9, 2315–2329, doi:10.3762/bjnano.9.216

• (EVA) encapsulation (Figure 3). The front of the basic solar cell structure consists of transparent conductive oxide (e.g., indium tin oxide (ITO)), a thin p-doped and intrinsic amorphous silicon (a-Si:H) layer for electrical passivation, a slightly n-doped crystalline Si (c-Si) wafer (absorber), and

• carriers from the c-Si wafer and neglected contributions of carriers from thin amorphous layers (replicating state-of-the-art devices). Under this realistic assumption, the A can be assumed to be equal to the external quantum efficiency, EQE, of the device [18]. In this case, the potential JSC of the solar

Intrinsic ultrasmall nanoscale silicon turns n-/p-type with SiO₂/Si₃N₄-coating

• Dirk König,
• Daniel Hiller,
• Noël Wilck,
• Birger Berghoff,
• Merlin Müller,
• Sangeeta Thakur,
• Giovanni Di Santo,
• Luca Petaccia,
• Joachim Mayer,
• Sean Smith and
• Joachim Knoch

Beilstein J. Nanotechnol. 2018, 9, 2255–2264, doi:10.3762/bjnano.9.210

• electronic DOS were calculated from MO eigenenergies, applying a Gaussian broadening of 0.2 eV. Sample preparation Samples comprising a Si3N4-embedded NWell were fabricated by plasma-enhanced chemical vapour deposition (PECVD) using SiH4+NH3+N2 for Si3N4 and SiH4+Ar for amorphous Si [24]. As substrates, n

• respective energy values as extracted from the spectra (dashed lines). The light green and cyan lines show the background fit of the amorphous Si3N4-matrix. The lower signal-to-noise ratio for Si-NWells embedded in Si3N4 as compared to SiO2 is comprehensively evaluated and discussed in Supporting Information

Lead-free hybrid perovskites for photovoltaics

• Oleksandr Stroyuk

Beilstein J. Nanotechnol. 2018, 9, 2209–2235, doi:10.3762/bjnano.9.207

• , respectively, and CB/VB positions suitable for most of ETL/HTL combinations (Figure 2d) [90]. Amorphous MA3Sb2I9 films were reported to have a bandgap of 2.14 eV and relatively high absorption coefficients of an order of 105 cm−1 [153]. The films also demonstrated considerable sub-bandgap absorption with a

• characteristic Urbach energy of ≈60 meV, indicating a substantial level of structural and energetic disorder. Due to the disorder, planar inverted solar cells based on amorphous MA3Sb2I9 showed low photocurrent densities, however, with a relatively high open-circuit voltage (≈890 meV) and a decent fill factor

Electrospun one-dimensional nanostructures: a new horizon for gas sensing materials

• Muhammad Imran,
• Nunzio Motta and
• Mahnaz Shafiei

Beilstein J. Nanotechnol. 2018, 9, 2128–2170, doi:10.3762/bjnano.9.202

• type of ZnO doping is with indium, for which the product is called “IZO”. When the amount of indium is greater than 0.05, amorphous In2O3 forms and leads to a pronounced decrease in grain size. The optical band gap energy of IZO NTs also decreases with increased doping levels. Doped indium atoms may

• exist as trivalent cations that act as donor impurities at the substitutional sites of Zn2+, or may be present in amorphous In2O3. Both forms of In3+ may significantly influence gas sensing performance due to an increase in the number of free electrons. TEM images show the tubular structure of IZO with

Spin-coated planar Sb₂S₃ hybrid solar cells approaching 5% efficiency

• Pascal Kaienburg,
• Benjamin Klingebiel and
• Thomas Kirchartz

Beilstein J. Nanotechnol. 2018, 9, 2114–2124, doi:10.3762/bjnano.9.200

• , spin-coating of different antimony- and sulfur-containing precursors was proposed [29][36][37]. A metal-organic complex is formed in solution which is then spin-coated and afterwards thermally decomposed. Just like for CBD [2][41] or ALD [22][32] the resulting amorphous film needs to be annealed at

• as Sb-TU route, and to the second process as Sb-BDC route. For both processes the spin-coated Sb-complex is thermally decomposed at around 200 °C leaving an amorphous film and then crystallized at higher temperatures in an inert atmosphere [29][37]. Details of the fabrication can be found in the

• that this slow annealing step drastically reduces the area of pinholes in the film. Both images in Figure 2a and 2b are taken after crystallization at 265 °C. The holes are already present in the amorphous films as can be seen in the corresponding images shown in Figure S1, Supporting Information File

Localized photodeposition of catalysts using nanophotonic resonances in silicon photocathodes

• Evgenia Kontoleta,
• Sven H. C. Askes,
• Lai-Hung Lai and
• Erik C. Garnett

Beilstein J. Nanotechnol. 2018, 9, 2097–2105, doi:10.3762/bjnano.9.198

• carriers (Figure 2). An 18 nm amorphous TiO2 layer was conformally deposited on the silicon nanostructures by using atomic layer deposition (ALD). This layer assists with charge separation, stabilizes the silicon surface and helps to passivate trap states, leading to well-known improvements in photo

• -electrochemical performance [39][40][41]. The amorphous TiO2 layer was further annealed at 350 °C for 3 h to form crystalline anatase TiO2, which led to an improved performance. The final TiO2 layers were characterized with X-ray diffraction (XRD) (Figure S2, Supporting Information File 1) and ellipsometry

High-throughput synthesis of modified Fresnel zone plate arrays via ion beam lithography

• Kahraman Keskinbora,
• Umut Tunca Sanli,
• Margarita Baluktsian,
• Corinne Grévent,
• Markus Weigand and
• Gisela Schütz

Beilstein J. Nanotechnol. 2018, 9, 2049–2056, doi:10.3762/bjnano.9.194

• transparent substrate followed by direct-write lithography (Figure 1a). The gold thin films were deposited on commercially available amorphous silicon nitride membranes (50 nm thick Si3N4) as described in the experimental section. The ion beam lithography (IBL) was done using a scanning electron microscope

Recent highlights in nanoscale and mesoscale friction

• Andrea Vanossi,
• Dirk Dietzel,
• Andre Schirmeisen,
• Ernst Meyer,
• Rémy Pawlak,
• Thilo Glatzel,
• Marcin Kisiel,
• Shigeki Kawai and
• Nicola Manini

Beilstein J. Nanotechnol. 2018, 9, 1995–2014, doi:10.3762/bjnano.9.190

• result, in vacuum, friction depends heavily on the arrangement, be it crystalline or amorphous, and the chemical nature of the surface atoms of the contacting bodies. For this reason, research in the last quarter of a century has focused on the mechanisms occurring at the atomic scale, which are

• experiments of gold and antimony nanoparticles on highly oriented pyrolithic graphite (HOPG) [46], where the precise value of γ was found to depend sensitively on the crystallinity of the particles. As predicted theoretically [66][67], γ = 0.5 was found for the case of amorphous Sb nanoparticles, whereas

• crystalline gold nanoparticles can be described by an effective scaling exponent of approximately half this value. This difference can be understood simply by considering how force cancellation effects become less effective for amorphous interfaces with irregular positioning of slider atoms [46]. While the

Defect formation in multiwalled carbon nanotubes under low-energy He and Ne ion irradiation

• Santhana Eswara,
• Jean-Nicolas Audinot,
• Brahime El Adib,
• Maël Guennou,
• Tom Wirtz and
• Patrick Philipp

Beilstein J. Nanotechnol. 2018, 9, 1951–1963, doi:10.3762/bjnano.9.186

• irradiation to study the influence of fluence and sample thickness on the irradiation-induced damage of multiwalled carbon nanotubes (MWCNTs). The irradiated areas have been characterised by correlative Raman spectroscopy and TEM imaging. In order to preclude the Raman contribution coming from the amorphous

• keV He+ irradiation for a relatively low fluence of 8 × 1014 ions/cm2 before the sample turns amorphous [13]. Transforming graphene into fullerenes has been carried out by electron irradiation [14], and graphitic nanostripes have been obtained from SiC by MeV Ta or Pb irradiation [15]. In addition

• sputter yield. A similar ratio between sputter yields from sample top and bottom has been found for Hobler at al. for 20 keV Ar irradiation of amorphous Si membrane when sputtering from the top surface is maximum [50]. They showed that this maximum corresponds to a sample thickness which is equal to the

Synthesis of a MnO₂/Fe₃O₄/diatomite nanocomposite as an efficient heterogeneous Fenton-like catalyst for methylene blue degradation

• Zishun Li,
• Xuekun Tang,
• Kun Liu,
• Jing Huang,
• Yueyang Xu,
• Qian Peng and
• Minlin Ao

Beilstein J. Nanotechnol. 2018, 9, 1940–1950, doi:10.3762/bjnano.9.185

• support of carriers, the prepared composites possess a much higher specific surface area, which further enhances the adsorption and the consecutive degradation performance of the catalysts. Diatomite, a natural porous mineral originating from the fossilization of diatom shells, is composed of amorphous

• , a broad peak at around 22.5° is observed due to the amorphous structure of SiO2. No other obvious diffraction peaks are detected, suggesting that after the washing, the raw diatomite is highly pure. Six peaks at 29.9°, 35.3°, 43.2°, 53.3°, 57.00° and 62.4° are observed in the pattern of Fe3O4

• . However, the original characteristic peaks of magnetite are weakened. This indicates that the nano-MnO2 covering on the Fe3O4/diatomite is of low crystallinity or amorphous. Figure 2 shows the FTIR spectra of purified diatomite, Fe3O4/diatomite and MnO2/Fe3O4/diatomite. The broad peaks at 3400 and 1630 cm

A differential Hall effect measurement method with sub-nanometre resolution for active dopant concentration profiling in ultrathin doped Si_1−xGe_x and Si layers

• Richard Daubriac,
• Emmanuel Scheid,
• Hiba Rizk,
• Richard Monflier,
• Sylvain Joblot,
• Rémi Beneyton,
• Pablo Acosta Alba,
• Sébastien Kerdilès and
• Filadelfo Cristiano

Beilstein J. Nanotechnol. 2018, 9, 1926–1939, doi:10.3762/bjnano.9.184

• continuous amorphous layer. Then, we compare electrical parameters measured by conventional Hall effect with the evolution of the crystal structure imaged by TEM as functions of the laser energy densities. The TEM analysis (Figure S11, Supporting Information File 1) shows that for energies of 0.74 and 0.76 J

• melt the surface. In contrast, following a LTA at 0.79 J·cm−2 the SiGe top layer is completely amorphous, clearly indicating that in this case the whole SiGe layer was molten, leaving no seed for a perfect recrystallization. The threshold energy for surface melt is therefore located between 0.76 and

Synthesis of carbon nanowalls from a single-source metal-organic precursor

• André Giese,
• Sebastian Schipporeit,
• Volker Buck and
• Nicolas Wöhrl

Beilstein J. Nanotechnol. 2018, 9, 1895–1905, doi:10.3762/bjnano.9.181

• amorphous carbon. Combining the two values one can deduce that the synthesized material is almost entirely sp2-bonded nanocrystalline graphite with almost no carbon being sp3-bonded. The heights of the CNWs were also obtained from the cross-sectional SEM pictures in Figure 3 and Figure 4 and plotted in a

Synthesis of hafnium nanoparticles and hafnium nanoparticle films by gas condensation and energetic deposition

• Irini Michelakaki,
• Nikos Boukos,
• Dimitrios A. Dragatogiannis,
• Spyros Stathopoulos,
• Costas A. Charitidis and
• Dimitris Tsoukalas

Beilstein J. Nanotechnol. 2018, 9, 1868–1880, doi:10.3762/bjnano.9.179

• corresponding to the (10−10) crystal planes of hexagonal close-packed (hcp) Hf (Figure 2, regions A, JCPDS 00-038-1478). In the shell, the coexistence of nanocrystallites of orthorhombic HfO2 (Figure 2, regions with arrows) within amorphous regions is observed. The distance between adjacent planes in the shell

• boundaries, where a broad spectrum of interatomic distances exist. The resulting X-ray diffraction pattern appears very similar to that of an amorphous material. Additionally, from the X-ray patterns, it is observed that the relative intensity of the peaks HfO2 and Hf IHfO2/IHf decreases with increasing the

• composed of orthorhombic HfO2 nanocrystallites indicated by arrows exhibiting lattice fringes of d = 0.295 nm corresponding to (101) HfO2 embedded in an amorphous layer. X-ray pattern of hafnium NPs on Si substrate synthesized for different aggregation-zone lengths D = 50, 75 and 100 nm. a) Bright-field

Uniform cobalt nanoparticles embedded in hexagonal mesoporous nanoplates as a magnetically separable, recyclable adsorbent

• Can Zhao,
• Yuexiao Song,
• Tianyu Xiang,
• Wenxiu Qu,
• Shuo Lou,
• Xiaohong Yin and
• Feng Xin

Beilstein J. Nanotechnol. 2018, 9, 1770–1781, doi:10.3762/bjnano.9.168

• of the sp2 carbon atoms in amorphous and graphitic carbon, respectively [22][37]. The intensity ratio of ID/IG (I represents the intensity of the D and G peaks) for the hexagonal magnetic mesoporous sample NPLs-2.5-800 is determined to be 1.02, indicating most of the carbon is amorphous in structure

Increasing the performance of a superconducting spin valve using a Heusler alloy

• Andrey A. Kamashev,
• Aidar A. Validov,
• Joachim Schumann,
• Vladislav Kataev,
• Bernd Büchner,
• Yakov V. Fominov and
• Ilgiz A. Garifullin

Beilstein J. Nanotechnol. 2018, 9, 1764–1769, doi:10.3762/bjnano.9.167

• this respect it would be very interesting to explore theoretically and experimentally the option of optimization of the F1 layer in the SSV AFM/F1/N1/F2/N2/S heterostructure. Recently, Singh et al. [32] reported a huge SSV effect for a S/F1/N/F2 structure made of amorphous MoGe, Ni, Cu and CrO2 as S

Controllable one-pot synthesis of uniform colloidal TiO₂ particles in a mixed solvent solution for photocatalysis

• Jong Tae Moon,
• Seung Ki Lee and
• Ji Bong Joo

Beilstein J. Nanotechnol. 2018, 9, 1715–1727, doi:10.3762/bjnano.9.163

• particles. When uniform, amorphous TiO2 particles were calcined at an optimal temperature (500 °C), the final sample exhibited beneficial characteristics such as high anatase crystallinity with a mixed phase of anatase and rutile and relatively high surface area. The photocatalytic efficiency of the uniform

• TiO2 precursor. Specifically, a typical synthesis involves three steps, as illustrated in Scheme 1: 1) the formation of TiO2 nucleates and subsequent growth of amorphous TiO2 spheres by a sol–gel reaction of titanium butoxide (TBOT) in the mixed solvent with hydroxypropylcellulose (HPC) as a surfactant

• ; 2) aging step of the spherical TiO2 particles in the water-containing solvent to make the surface of TiO2 particles condensed; and 3) calcination to crystallize amorphous TiO2 particles into their crystallized counterparts. The hydrolysis and condensation of the TBOT precursor are highly influenced

Friction force microscopy of tribochemistry and interfacial ageing for the SiO_x/Si/Au system

• Christiane Petzold,
• Marcus Koch and
• Roland Bennewitz

Beilstein J. Nanotechnol. 2018, 9, 1647–1658, doi:10.3762/bjnano.9.157

• Au layer, while no adhesive Cr layer could be distinguished between Si and Au. An amorphous layer (marked with asterisk in Figure 7) with a thickness of about 13 nm covers the surface that had been in sliding contact with Au(111). A rather sharp border marks the transition from amorphous Si to

• crystalline Si (Figure 7d). If the amorphous layer contained significant amounts of oxygen, it would appear brighter than the crystalline silicon. This was not the case and we conclude that the amorphization is a mechanical process that does not require oxidation to occur. Fourier transformation of the images

• (right side of Figure 7) revealed crystalline order for the tip material lattice and amorphous short-range structure for the layer that was transformed by the sliding contact. Discussion We start by discussing the absence of contact ageing in our slide–hold–slide experiments by AFM in ultrahigh vacuum