Comprehensive investigation of the electronic excitation of W(CO)₆ by photoabsorption and theoretical analysis in the energy region from 3.9 to 10.8 eV

• Mónica Mendes,
• Khrystyna Regeta,
• Filipe Ferreira da Silva,
• Nykola C. Jones,
• Søren Vrønning Hoffmann,
• Gustavo García,
• Chantal Daniel and
• Paulo Limão-Vieira

Beilstein J. Nanotechnol. 2017, 8, 2208–2218, doi:10.3762/bjnano.8.220

• studies of W(CO)6 in the photon energy range of 3.9–10.8 eV (Figure 1) were performed at the AU-UV beam line of the ASTRID2 synchrotron facility, Aarhus University, Denmark. The experimental setup has been described previously [31], with recent modifications reported in detail by Palmer et al. [34

• transitions The measured high-resolution VUV photoabsorption spectrum is presented in Figure 1, in the photon energy range from 3.9 to 10.8 eV, and the proposed assignments are summarised in Table 1 based on the vibrational spectra of Amster et al. [18], Broquier et al. [19] and the infrared data of Jones [20

• spectral assignments are shown in Table 2 and Figure 4. This is the most intense band within the photon energy range studied and corresponds mostly to the 21T1u←11A1g MLCT transition involving the contribution from (3t2u←4t2g) (0.64) and (12t1u←4t2g) (0.31) (Table 1) calculated at 6.106 eV with a large

Angstrom-scale flatness using selective nanoscale etching

• Takashi Yatsui,
• Hiroshi Saito and
• Katsuyuki Nobusada

Beilstein J. Nanotechnol. 2017, 8, 2181–2185, doi:10.3762/bjnano.8.217

• , we have developed a near-field etching technique. In this process, the molecules are dissociated by an ONF with a lower photon energy than that of the molecules (see Figure 1). When light irradiates the substrate, the ONF is generated only at the protrusions because of their non-uniformity

• continuous-wave diode-pumped solid-state (DPSS) laser (λ = 532 nm; 2.33 eV; excitation power: 119.4 W/cm2). Thus, the incident photon energy was lower than the dissociation energy of Cl2 (3.10 eV) [11] and the hypochlorous acid (3.35 eV) [12]; therefore, the Cl2 or hypochlorous acid dissociated on the

• protrusions only. In the solution, a light source with a photon energy of 4.66 eV (higher than the dissociation energy) dissociated the hypochlorous acid and consequently produced Cl radicals [13]. This process is expected to be similar to the etching of glass when Cl2 gas is used. The laser light was

Identifying the nature of surface chemical modification for directed self-assembly of block copolymers

• Laura Evangelio,
• Federico Gramazio,
• Matteo Lorenzoni,
• Michaela Gorgoi,
• Francisco Miguel Espinosa,
• Ricardo García,
• Francesc Pérez-Murano and
• Jordi Fraxedas

Beilstein J. Nanotechnol. 2017, 8, 1972–1981, doi:10.3762/bjnano.8.198

• more than 20 nm for polymeric materials [15]. HAXPES reaches its full potential when using synchrotron radiation as an excitation source since, in this case, photon energy (and thus kinetic energy) can be tuned so that the probing depth can be also varied in a controlled and continuous manner

• affinity to PMMA (more efficient although non complete wetting). This is further confirmed when the C 1s HAXPES spectra are taken at different photon energies, as shown in Figure 5c,d, where the spectra have been acquired at 2700 and 3000 eV, respectively. Increasing photon energy implies increasing

• located on top of the Si/SiO2 interface, as schematized in Figure 7a, since it is the first feature that appears at the lower photon energy used. In addition, since the feature at 1844 eV exhibits a lower binding energy as compared to the 1846 eV counterpart, it can be assigned to a substoichiometric

Coexistence of strongly buckled germanene phases on Al(111)

• Weimin Wang and
• Roger I. G. Uhrberg

Beilstein J. Nanotechnol. 2017, 8, 1946–1951, doi:10.3762/bjnano.8.195

• , obtained at a photon energy of 130 eV, was fitted by four components of which one only corresponded to 1 or 2% of the total intensity. The other three components were assigned to three groups of atoms that could be defined from the model. The assignment proposed in [15] implied that the 3d intensity from

• colored green and labeled Ge(8), the other Ge atoms are colored orange, Al atoms are colored light blue, except for the first layer Al atoms which are colored grey. The Ge(4) atom gives rise to the hexagonal pattern observed by STM. Ge 3d core-level spectrum obtained at a photon energy of 135 eV in normal

• components are not given in [15], so a quantitative evaluation is difficult. In Figure 4, we present a Ge 3d core-level spectrum obtained from a surface on which the (3×3) reconstruction was dominating, as verified by LEED patterns at different electron energies. The spectrum was measured using a photon

(Metallo)porphyrins for potential materials science applications

• Lars Smykalla,
• Carola Mende,
• Michael Fronk,
• Pablo F. Siles,
• Michael Hietschold,
• Georgeta Salvan,
• Dietrich R. T. Zahn,
• Oliver G. Schmidt,
• Tobias Rüffer and
• Heinrich Lang

Beilstein J. Nanotechnol. 2017, 8, 1786–1800, doi:10.3762/bjnano.8.180

• -optical Kerr effect (MOKE) measurements would be very interesting. Moreover, as MOKE measurements allow one to address magnetic properties with both high sensitivity and high spatial resolution, magneto-optical techniques in the visible or X-ray photon energy range have been supposed to be important for

• the integration of single-molecule magnets into spintronic or quantum computing devices [12]. For the design of such devices the knowledge of the photon energy at which the MOKE is largest in magnitude is of crucial importance. The number of reports on spectroscopic MOKE investigations are very

Fluorination of vertically aligned carbon nanotubes: from CF₄ plasma chemistry to surface functionalization

• Claudia Struzzi,
• Mattia Scardamaglia,
• Jean-François Colomer,
• Alberto Verdini,
• Luca Floreano,
• Rony Snyders and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2017, 8, 1723–1733, doi:10.3762/bjnano.8.173

• ], confirming the depletion of the pristine graphitization level previously observed in Raman spectra (Figure 4). Additional peaks appear at 287, 288.6 and 290.8 eV and they are more evident for high fluorine content (blue curve), as indicated by the black bars over the photon energy axis. These features are

• indicative for covalent bond formation [31][38] and, in correspondence to them, we can observe the presence of broad peaks in the F–K edge at 690.2, 692.4 and 696 eV photon energy. These resonances correspond to the excitations from the F1s to σ* states due to the covalent interaction between F and C atoms

• (≈1 eV) and an Ar ion gun (≤10 eV) is used. The valence band (VB) spectra are measured with 140 eV photon energy in the ALOISA experimental chamber at the Elettra synchrotron radiation facility (Italy) [40]. The base pressure is within 10−10 mTorr range. Photoelectrons are collected at normal emission

Two-dimensional carbon-based nanocomposites for photocatalytic energy generation and environmental remediation applications

• Suneel Kumar,
• Ashish Kumar,
• Ashish Bahuguna,
• Vipul Sharma and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2017, 8, 1571–1600, doi:10.3762/bjnano.8.159

Study of the surface properties of ZnO nanocolumns used for thin-film solar cells

• Neda Neykova,
• Jiri Stuchlik,
• Karel Hruska,
• Ales Poruba,
• Zdenek Remes and
• Ognen Pop-Georgievski

Beilstein J. Nanotechnol. 2017, 8, 446–451, doi:10.3762/bjnano.8.48

• -plasma for 1, 5, 10 and 25 min. The measured PDS absorptance spectra reflect the absorption edge, Urbach tail, absorption on defects and free-carrier absorption (proportional to the concentration of free carriers). All optical absorptance spectra show the optical absorption edge at a photon energy of 3.3

Selective photodissociation of tailored molecular tags as a tool for quantum optics

• Ugur Sezer,
• Philipp Geyer,
• Moritz Kriegleder,
• Maxime Debiossac,
• Armin Shayeghi,
• Markus Arndt,
• Lukas Felix and
• Marcel Mayor

Beilstein J. Nanotechnol. 2017, 8, 325–333, doi:10.3762/bjnano.8.35

• yet generally scalable to covalently bound organic molecules. In particular, large biomolecules – which are interesting candidates for quantum-interference experiments and gas-phase metrology [7] – often neither ionize nor dissociate upon absorption of a single photon, not even at 7.9 eV photon energy

• [21]. Here we address this challenge and study tailored tags that are optimized to respond to light of lower photon energy with cleavage at a deterministic location. Click chemistry shall then allow attaching them to a wide class of analyte molecules and thus solve the problem. Results Design of the

• sections at 254 nm and 366 nm – but faster decay at higher photon energy. Preliminary dissociation experiments at 355 nm did not reveal any major cleavage of the trimer 1 at the laser energies that were sufficient to cleave the monomer 4 at 266 nm. Because of this, the following experiments were performed

Photo-ignition process of multiwall carbon nanotubes and ferrocene by continuous wave Xe lamp illumination

• Paolo Visconti,
• Patrizio Primiceri,
• Daniele Longo,
• Luciano Strafella,
• Paolo Carlucci,
• Mauro Lomascolo,
• Arianna Cretì and
• Giuseppe Mele

Beilstein J. Nanotechnol. 2017, 8, 134–144, doi:10.3762/bjnano.8.14

• point of view, the suggested evolution of ignition process has been summarized in the Figure 17. As reported in Figure 17, the photo-induced process of charge separation, promoted by UV–vis–IR light irradiation (photon energy h∙ν = h∙c/λ with 380 nm < λ < 1000 nm, c speed of light and h Planck constant

Cubic chemically ordered FeRh and FeCo nanomagnets prepared by mass-selected low-energy cluster-beam deposition: a comparative study

• Veronique Dupuis,
• Anthony Robert,
• Arnaud Hillion,
• Ghassan Khadra,
• Nils Blanc,
• Damien Le Roy,
• Florent Tournus,
• Clement Albin,
• Olivier Boisron and
• Alexandre Tamion

Beilstein J. Nanotechnol. 2016, 7, 1850–1860, doi:10.3762/bjnano.7.177

• nanoparticles up to m = 12, our largest size. To go a step further in the investigation of the chemical ordering in FeCo, we used anomalous X-ray diffraction (AXD) in order to experimentally overcome the low “Z-contrast” between Fe and Co. This was achieved by changing the X-ray wavelength (or photon energy) by

• the absorption edge for heavy atoms [16]. From Figure 6, we found that a photon energy of 7.108 keV just before the Fe K absorption edge gave a maximum of anomalous contrast for the atomic scattering factor equal to nine for FeCo, larger than the atomic contrast (ΔZFeCo = 1). Thus, mass-selected 5 nm

• ″ coefficients as a function of photon energy for Fe, Co and Rh elements in the range of Fe and Co K edges. Measured X-ray scattering at 7.108 keV on annealed FeCo nanoparticles with 5 nm in diameter. (a) ZFC/FC and m(H) experimental data for mass-selected as-prepared FeCo clusters with 4.3 nm in diameter along

Precise in situ etch depth control of multilayered III−V semiconductor samples with reflectance anisotropy spectroscopy (RAS) equipment

• Ann-Kathrin Kleinschmidt,
• Lars Barzen,
• Johannes Strassner,
• Christoph Doering,
• Henning Fouckhardt,
• Wolfgang Bock,
• Michael Wahl and
• Michael Kopnarski

Beilstein J. Nanotechnol. 2016, 7, 1783–1793, doi:10.3762/bjnano.7.171

• thickness (the latter either increasing during an epitaxial process or diminishing during dry-etching). The current thickness of the etched layer can be determined in situ from single photon energy transients of just the average reflected intensity and, hence, any required etch depth can be achieved. Due to

• photon energy, the term RAS spectrum will be used. Due to the rotation of the substrates during epitaxy the software of the epitaxy-RAS instrumentation typically ignores the sign of the RAS signal. The time evolution of the spectrum of this RAS signal is called a false-color plot or short color plot (see

• techniques (as, e.g., reflection high-energy electron diffraction (RHEED)), which might not be applicable in some set-ups. Recording a RAS color plot is time-consuming, i.e., monitoring a single RAS spectrum from 1.5–5.0 eV photon energy with a step size of 0.1 eV during reactive ion etching (the substrate

Filled and empty states of Zn-TPP films deposited on Fe(001)-p(1×1)O

• Gianlorenzo Bussetti,
• Alberto Calloni,
• Rossella Yivlialin,
• Andrea Picone,
• Federico Bottegoni and
• Marco Finazzi

Beilstein J. Nanotechnol. 2016, 7, 1527–1531, doi:10.3762/bjnano.7.146

• ][26]. The IPES energy resolution is about 700 meV. All the experiments reported here were achieved under negligible charging conditions during electron spectroscopy data acquisition. The position of the vacuum level was obtained by adding the photon energy to the low-energy secondary electron cutoff

Manufacturing and investigation of physical properties of polyacrylonitrile nanofibre composites with SiO₂, TiO₂ and Bi₂O₃ nanoparticles

• Tomasz Tański,
• Wiktor Matysiak and
• Barbara Hajduk

Beilstein J. Nanotechnol. 2016, 7, 1141–1155, doi:10.3762/bjnano.7.106

• , and with Equation 6, the relationship [(4πk/λ)hν]2 was determined as a function of the photon energy. Then, using the method of least squares, a linear function was fitted to the straight parts of the curves, showing the highest slope (Figure 11). The x-intercept of the fitted linear functions

• layers. The dependence (αhν)2 as a function of the photon energy. Left: the fit obtained from the UV–vis analysis (absorbance vs wavelength). Right: the fit obtained from ellipsometry analysis (extinction as a function of wavelength). The results of ellipsometric measurements of the thickness of the

Photocurrent generation in carbon nanotube/cubic-phase HfO₂ nanoparticle hybrid nanocomposites

• Protima Rauwel,
• Augustinas Galeckas,
• Martin Salumaa,
• Frédérique Ducroquet and
• Erwan Rauwel

Beilstein J. Nanotechnol. 2016, 7, 1075–1085, doi:10.3762/bjnano.7.101

• Figure 2. The fine structure of the absorption spectrum in the UV–vis region revealed upon background subtraction and ×100-fold magnification is represented by the grey curve in Figure 2a. One can observe an apparent double feature in the absorption spectrum in the photon energy region 1.5–3.5 eV, where

• the structure. The photon energy range from 2 to 3 eV is identified in the literature as the typical response of the luminescent extrinsic centers associated with surface defects or impurities introduced during the synthesis of the nanoparticles. In particular, the characteristic green luminescence at

The role of morphology and coupling of gold nanoparticles in optical breakdown during picosecond pulse exposures

• Yevgeniy R. Davletshin and
• J. Carl Kumaradas

Beilstein J. Nanotechnol. 2016, 7, 869–880, doi:10.3762/bjnano.7.79

• ]) since the photon energy at this time-scale is transferred to the electrons in the gold nanoparticle and diffusion is minimized [39][40]. The gold nanoparticles therefore retain their optical properties during LIB with pulses shorter than 10 ps. Compared to femtosecond lasers, ultrashort picosecond

Case studies on the formation of chalcogenide self-assembled monolayers on surfaces and dissociative processes

• Yongfeng Tong,
• Tingming Jiang,
• Azzedine Bendounan,
• Makri Nimbegondi Kotresh Harish,
• Angelo Giglia,
• Stefan Kubsky,
• Fausto Sirotti,
• Luca Pasquali,
• Srinivasan Sampath and
• Vladimir A. Esaulov

Beilstein J. Nanotechnol. 2016, 7, 263–277, doi:10.3762/bjnano.7.24

• resolution was 500 meV. The binding energy in the XPS spectra was calibrated with respect to the Au 4f7/2 peak, set at 84 eV. The calibration error is estimated to be 50 meV at TEMPO and about 100 meV at BEAR. With some exceptions (indicated later in the text), we used a photon energy corresponding to a

Impact of ultrasonic dispersion on the photocatalytic activity of titania aggregates

• Hoai Nga Le,
• Frank Babick,
• Klaus Kühn,
• Minh Tan Nguyen,
• Michael Stintz and
• Gianaurelio Cuniberti

Beilstein J. Nanotechnol. 2015, 6, 2423–2430, doi:10.3762/bjnano.6.250

• energy of the incident beam. In UV range, where radiation is adequate for TiO2 photocatalytic activation (appropriate for the photon energy of 3.2 eV and a wavelength of 387 nm [2][22][34][35]), the independence of transmittance as a function of the photocatalyst size is no longer valid as it is in the

Self-organization of gold nanoparticles on silanated surfaces

• Htet H. Kyaw,
• Salim H. Al-Harthi,
• Azzouz Sellai and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2015, 6, 2345–2353, doi:10.3762/bjnano.6.242

• electron emission after APTES was deposited on the glass substrate and AuNPs were deposited on the APTES-functionalized glass substrate. The work function (Φ) can be calculated from the difference in the photon energy of He(I) (21.2 eV) and the energy difference ΔE between the secondary cut-off energy

Plasma fluorination of vertically aligned carbon nanotubes: functionalization and thermal stability

• Claudia Struzzi,
• Mattia Scardamaglia,
• Axel Hemberg,
• Luca Petaccia,
• Jean-François Colomer,
• Rony Snyders and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2015, 6, 2263–2271, doi:10.3762/bjnano.6.232

• surface during the measurements, a dual beam charge neutralization composed of an electron gun (≈1 eV) and an Ar ion gun (≤10 eV) was used. The valence band investigation was performed using an excitation photon energy of hν = 31 eV from a horizontally polarized (p-polarized) synchrotron light source at

• O 2p-like states and F 2p-like states are almost the same when using a photon energy of hν = 31 eV, it can be suggested that, when in high amounts, the structure generated by fluorine atoms prevails over that of oxygen-related states in valence band spectra. Fluorine atoms mainly bind to carbon

• . UPS spectra acquired with a photon energy of hν = 31 eV, the red line is the pristine vCNT sample, the blue is the functionalized, annealed (T = 300 °C) sample, the black and the green lines are related to samples heated at 500 and 900 °C, respectively. Raman spectra acquired on pristine

Influence of wide band gap oxide substrates on the photoelectrochemical properties and structural disorder of CdS nanoparticles grown by the successive ionic layer adsorption and reaction (SILAR) method

• Mikalai V. Malashchonak,
• Alexander V. Mazanik,
• Olga V. Korolik,
• Еugene А. Streltsov and
• Anatoly I. Kulak

Beilstein J. Nanotechnol. 2015, 6, 2252–2262, doi:10.3762/bjnano.6.231

• reprecipitation during the photocorrosion process. It should be noted that the oxide (ZnO, TiO2, In2O3)/CdS heterostructures are characterized by relatively high IPCE values of up to 60–90% at a photon energy of about 3 eV. This is due to the intimate contact of SILAR-deposited CdS nanoparticles with the

• NPs is reduced to hν due to weakening of the quantum-confinement effect. For this reason, at an early stage in the SILAR process, the signal intensity grows faster than the CdS amount. Due to the further weakening of the quantum-confinement effect in CdS nanoparticles, at larger N, the photon energy

Improved optical limiting performance of laser-ablation-generated metal nanoparticles due to silica-microsphere-induced local field enhancement

• Zheren Du,
• Lianwei Chen,
• Tsung-Sheng Kao,
• Mengxue Wu and
• Minghui Hong

Beilstein J. Nanotechnol. 2015, 6, 1199–1204, doi:10.3762/bjnano.6.122

• transmission through the dispersion as shown in Figure 2a. The optical limiting effect of the nanoparticles appears upon formation of microbubbles. The bubble formation occurs at the solvent–nanoparticle interface. The absorbed photon energy by the nanoparticle is dissipated as heat to the surrounding solvent

Characterization of nanostructured ZnO thin films deposited through vacuum evaporation

• Jose Alberto Alvarado,
• Arturo Maldonado,
• Héctor Juarez,
• Mauricio Pacio and
• Rene Perez

Beilstein J. Nanotechnol. 2015, 6, 971–975, doi:10.3762/bjnano.6.100

• transmittance by using Equation 1: where d is the thickness of the thin film, and T is measured transmission. In consequence, the relation between the coefficient and the photon energy for direct transition is , where A is a constant, Eg is the optical band gap, the plot of this relation has a linear region

Applications of three-dimensional carbon nanotube networks

• Manuela Scarselli,
• Paola Castrucci,
• Francesco De Nicola,
• Ilaria Cacciotti,
• Francesca Nanni,
• Emanuela Gatto,
• Mariano Venanzi and
• Maurizio De Crescenzi

Beilstein J. Nanotechnol. 2015, 6, 792–798, doi:10.3762/bjnano.6.82

• remove different types of oil has been demonstrated and can be considered very interesting for environmental applications. In addition, the CNT network shows a good photo response to incident light in the visible and near ultraviolet range, thus proving its potential application in photon-energy

Graphene quantum interference photodetector

• Mahbub Alam and
• Paul L. Voss

Beilstein J. Nanotechnol. 2015, 6, 726–735, doi:10.3762/bjnano.6.74

• % for the device. The results of the interaction of light with the zigzag and armchair structures are shown in Figure 5 and Figure 6, respectively. For this simulation, the parameters used for the zigzag structure were an applied voltage of 0.1 eV, photon energy of 0.26 eV and a photon flux of 1025

• photon/m2/s (4.16 × 106 W/m2). The parameters used for armchair structure were an applied voltage of 0.1 eV, photon energy of 0.13 eV and a photon flux of 1025 photon/m2/s (2.08 × 106 W/m2). For both the zigzag and armchair structures, the polarization of the applied electromagnetic field was along the

• variation of light. With the appropriate bias, the device can also be used to detect the photon energy corresponding to the energy difference of any two resonant levels. The peak photocurrent variations with different photon energies are shown in Figure 8a and Figure 8b corresponding to zigzag and armchair