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Search for "band gap" in Full Text gives 273 result(s) in Beilstein Journal of Nanotechnology. Showing first 200.

Nanocrystalline ZrO2 and Pt-doped ZrO2 catalysts for low-temperature CO oxidation

  • Amit Singhania and
  • Shipra Mital Gupta

Beilstein J. Nanotechnol. 2017, 8, 264–271, doi:10.3762/bjnano.8.29

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  • ceramic material and is widely used in the industry. It is a wide band gap semiconductor (5–7 eV) and is known for its unique mechanical, electrical, thermal, catalytic and optical capabilities [3][4]. ZrO2 finds a range of applications in different fields such as catalyst/support, as biomaterial [5], as
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Published 26 Jan 2017

Performance of colloidal CdS sensitized solar cells with ZnO nanorods/nanoparticles

  • Anurag Roy,
  • Partha Pratim Das,
  • Mukta Tathavadekar,
  • Sumita Das and
  • Parukuttyamma Sujatha Devi

Beilstein J. Nanotechnol. 2017, 8, 210–221, doi:10.3762/bjnano.8.23

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  • ; ZnO; Introduction Dye-sensitized solar cells (DSSCs) using inorganic semiconductors are being investigated as a cost-effective and alternative energy source. In DSSCs, a porous electrode made of a wide band gap semiconductor is required for anchoring dye molecules and transporting photo-injected
  • development of the so-called quantum dot sensitized solar cells (QDSSCs) [5][6][7][8][9]. Due to its natural abundance and comparatively lower cost, CdS, one of the important direct band II–VI semiconductors with a band gap of ≈2.4 eV, has been investigated for this purpose. According to the reported results
  • materials investigated so far, ZnO delivers effective performance owing to higher band gap (≈3.3 eV) and high electron mobility (≈200–300 cm2V−1S−1) compared to conventional TiO2 [28][29]. Also, the flexibility in morphological control and the possibility of low-temperature applications also indicates that
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Published 23 Jan 2017

Laser irradiation in water for the novel, scalable synthesis of black TiOx photocatalyst for environmental remediation

  • Massimo Zimbone,
  • Giuseppe Cacciato,
  • Mohamed Boutinguiza,
  • Vittorio Privitera and
  • Maria Grazia Grimaldi

Beilstein J. Nanotechnol. 2017, 8, 196–202, doi:10.3762/bjnano.8.21

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  • , abundance, nontoxicity and high activity. Unfortunately, its wide band gap (≈3.2 eV) in the UV portion of the spectrum makes it inefficient under solar illumination. Recently, so-called “black TiO2” has been proposed as a candidate to overcome this issue. However, typical synthesis routes require high
  • inertness (even in a corrosive environment), stability, abundance and nontoxicity. Nevertheless, its exploitation in environmental remediation, and in particular in water purification, is relatively limited due to its wide band gap (≈3.2 eV). This means that only 5% of the incoming solar radiation can be
  • readily employed for water decontamination. In order to enhance the photocatalytic performance of TiO2 under visible (solar) irradiation, many efforts have been made in the last years, ranging from doping with N, C and transition metals [7][8][9], to coupling with narrow band gap semiconductor quantum
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Published 19 Jan 2017

Optical and photocatalytic properties of TiO2 nanoplumes

  • Viviana Scuderi,
  • Massimo Zimbone,
  • Maria Miritello,
  • Giuseppe Nicotra,
  • Giuliana Impellizzeri and
  • Vittorio Privitera

Beilstein J. Nanotechnol. 2017, 8, 190–195, doi:10.3762/bjnano.8.20

Graphical Abstract
  • renewable energy generation but also in sustainable technology to remove dangerous contaminants from water [2][3][4][5][6]. In this context, TiO2 is one of the most extensively studied materials. However, TiO2 is characterized by a wide band gap (ca. 3 eV) resulting in a poor absorption of light in the
  • visible region [7]. Different approaches were proposed to overcome this limit: the inhibition of the recombination of photogenerated electrons and holes [8][9], the increase of the exposed surface area [10][11][12], and the decrease of the band-gap energy [13][14]. Recently, Chen et al. were able to
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Published 18 Jan 2017

Tunable plasmons in regular planar arrays of graphene nanoribbons with armchair and zigzag-shaped edges

  • Cristian Vacacela Gomez,
  • Michele Pisarra,
  • Mario Gravina and
  • Antonello Sindona

Beilstein J. Nanotechnol. 2017, 8, 172–182, doi:10.3762/bjnano.8.18

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  • additional property that they are semiconductors and their band gap is geometrically controllable. A clear picture of confined edge (interband) and surface (intraband) plasmons in GNRs, as wide as 100–500 nm, has been achieved by infrared imaging measurements on the nanoscale [26]. On the theoretical side
  • ZGNRs and AGNRs [36][37][38][39]. In particular, local spin-density calculations suggest the opening of a band gap larger than 0.1 eV in ZGNRs [36][37]. However, the LDA analysis of a virtually gapless GNR, i.e., 4ZGNR or 10ZGNR, in comparison with 5AGNR and 11AGNR, is particularly instructive to
  • observed in extrinsic 5AGNR subject to a positive doping of about 0.3 eV [31]. These outcomes are basically due to the different band-gap values of the two AGNRs, which according to our predictions are ca. 0.18 eV for 11AGNR, and ca. 0.36 eV for 5AGNR. Accordingly, less energy requirements are needed to
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Published 17 Jan 2017

Nitrogen-doped twisted graphene grown on copper by atmospheric pressure CVD from a decane precursor

  • Ivan V. Komissarov,
  • Nikolai G. Kovalchuk,
  • Vladimir A. Labunov,
  • Ksenia V. Girel,
  • Olga V. Korolik,
  • Mikhail S. Tivanov,
  • Algirdas Lazauskas,
  • Mindaugas Andrulevičius,
  • Tomas Tamulevičius,
  • Viktoras Grigaliūnas,
  • Šarunas Meškinis,
  • Sigitas Tamulevičius and
  • Serghej L. Prischepa

Beilstein J. Nanotechnol. 2017, 8, 145–158, doi:10.3762/bjnano.8.15

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  • be an ideal platform for the realization of the high-temperature zero-field quantum valley Hall effect [7]. From a practical point of view, the band gap opening in the electronic structure of graphene is quite attractive. It is expected that this will result in a new approach for application of
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Published 16 Jan 2017

Tandem polymer solar cells: simulation and optimization through a multiscale scheme

  • Fanan Wei,
  • Ligang Yao,
  • Fei Lan,
  • Guangyong Li and
  • Lianqing Liu

Beilstein J. Nanotechnol. 2017, 8, 123–133, doi:10.3762/bjnano.8.13

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  • the incident light achieves relatively better performance than the configuration with PCPDTBT/PCBM at the front. As a lower band gap, active material, PCPDTBT has considerably stronger optical absorption than P3HT. Thus, if the sub-cell with PCPDTBT is put first, a large portion of light energy will
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Published 12 Jan 2017

Nanocrystalline TiO2/SnO2 heterostructures for gas sensing

  • Barbara Lyson-Sypien,
  • Anna Kusior,
  • Mieczylaw Rekas,
  • Jan Zukrowski,
  • Marta Gajewska,
  • Katarzyna Michalow-Mauke,
  • Thomas Graule,
  • Marta Radecka and
  • Katarzyna Zakrzewska

Beilstein J. Nanotechnol. 2017, 8, 108–122, doi:10.3762/bjnano.8.12

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  • an n–n heterojunction, b) electron transfer from a TiO2 to a SnO2 grain providing active gas adsorption sites. EF: Fermi energy, EVB: valence band maximum energy, ECB: conduction band minimum energy, Eg: energy band gap, e−: electron, O−: singly ionized oxygen adatom. Comparison between XRD patterns
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Published 12 Jan 2017

Obtaining and doping of InAs-QD/GaAs(001) nanostructures by ion beam sputtering

  • Sergei N. Chebotarev,
  • Alexander S. Pashchenko,
  • Leonid S. Lunin,
  • Elena N. Zhivotova,
  • Georgy A. Erimeev and
  • Marina L. Lunina

Beilstein J. Nanotechnol. 2017, 8, 12–20, doi:10.3762/bjnano.8.2

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  • processes are longer in time and affect the photoluminescence intensity. The introduction of impurities creates donor levels in the GaAs band gap and the levels are efficient carrier-capture centers. Owing to this fact, the mechanisms of thermalization and recombination change. The electron lifetime at the
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Published 03 Jan 2017

Organoclay hybrid materials as precursors of porous ZnO/silica-clay heterostructures for photocatalytic applications

  • Marwa Akkari,
  • Pilar Aranda,
  • Abdessalem Ben Haj Amara and
  • Eduardo Ruiz-Hitzky

Beilstein J. Nanotechnol. 2016, 7, 1971–1982, doi:10.3762/bjnano.7.188

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  • photocatalytic degradation of organic pollutants [3][4][5][6]. It should be remembered that nanoparticulated zinc oxide is a wide-band gap II–VI semiconductor with a band-gap energy of around 3.4 eV, which is of great interest for photocatalytic applications [7]. ZnO nanoparticles (NP) have been assembled to
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Published 12 Dec 2016

Numerical investigation of depth profiling capabilities of helium and neon ions in ion microscopy

  • Patrick Philipp,
  • Lukasz Rzeznik and
  • Tom Wirtz

Beilstein J. Nanotechnol. 2016, 7, 1749–1760, doi:10.3762/bjnano.7.168

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  • conductivity of polymers [1]. A reduction of the band gap along with increasing photo- and electrical conductivity is observed for C+ implantation into poly(methyl methacrylate) (PMMA), which is related to the formation of carbon clusters with a polyaromatic structure [2]. Potential applications include
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Published 17 Nov 2016

Nanostructured TiO2-based gas sensors with enhanced sensitivity to reducing gases

  • Wojciech Maziarz,
  • Anna Kusior and
  • Anita Trenczek-Zajac

Beilstein J. Nanotechnol. 2016, 7, 1718–1726, doi:10.3762/bjnano.7.164

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  • as H2 [7], NO2 [8], NOx [9], CO [10], NH3 [11], H2S [12], and VOCs (i.e., methanol, ethanol, propanol [13], and acetone [14]). The influence of effective surface area on the gas sensing properties of TiO2 thin films is also frequently observed and investigated [15]. TiO2 is a wide-band gap
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Published 15 Nov 2016

Role of RGO support and irradiation source on the photocatalytic activity of CdS–ZnO semiconductor nanostructures

  • Suneel Kumar,
  • Rahul Sharma,
  • Vipul Sharma,
  • Gurunarayanan Harith,
  • Vaidyanathan Sivakumar and
  • Venkata Krishnan

Beilstein J. Nanotechnol. 2016, 7, 1684–1697, doi:10.3762/bjnano.7.161

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  • through, for example, modifying the band gap energy positions, influencing the generation and transport of charge carriers and altering the recombination rate. In this regard, physical parameters such as the support material and the irradiation source can also have significant effect on the activity of
  • longer electron life time than TiO2 [14][15][16]. Zinc oxide is a well-known semiconductor with a band gap energy of 3.37 eV and has been widely explored as photocatalytic material due to its non-toxic nature, high exciton binding energy (60 meV), photosensitivity and stability on exposure to high energy
  • radiation [17]. Due to this high band gap value, ZnO can only absorb ultraviolet (UV) light and this limits its practical applications [18]. Thus, in order to design more efficient photocatalysts, which are active in visible light, many research groups have devoted their studies towards dye sensitization
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Published 11 Nov 2016

Scanning probe microscopy studies on the adsorption of selected molecular dyes on titania

  • Jakub S. Prauzner-Bechcicki,
  • Lukasz Zajac,
  • Piotr Olszowski,
  • Res Jöhr,
  • Antoine Hinaut,
  • Thilo Glatzel,
  • Bartosz Such,
  • Ernst Meyer and
  • Marek Szymonski

Beilstein J. Nanotechnol. 2016, 7, 1642–1653, doi:10.3762/bjnano.7.156

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  • molecules or conducting polymers offer several advantages, e.g., they are relatively cheap to fabricate and can be used on flexible substrates [1]. The use of organic sensitizers allows even wide-band-gap semiconductors to be used in photovoltaic applications. Semiconductors with large band gaps offer
  • stability against photocorrosion at the expense of decreased sensitivity to the visible spectrum. A good example of this type of material is titanium dioxide, which has a band gap of 3.0–3.2 eV and absorbs only the ultraviolet part of the solar spectrum. Thus, bare TiO2 used in photovoltaic applications has
  • low conversion efficiencies [1]. However, when the surface of a wide-band-gap material is covered with a sensitizer that absorbs light in the visible spectrum and enables charge transfer through the semiconductor–adsorbate interface, the situation changes dramatically. The optical absorption, and
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Published 09 Nov 2016

Electric field induced structural colour tuning of a silver/titanium dioxide nanoparticle one-dimensional photonic crystal

  • Eduardo Aluicio-Sarduy,
  • Simone Callegari,
  • Diana Gisell Figueroa del Valle,
  • Andrea Desii,
  • Ilka Kriegel and
  • Francesco Scotognella

Beilstein J. Nanotechnol. 2016, 7, 1404–1410, doi:10.3762/bjnano.7.131

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  • interface with an applied electric field leads to an effective increase of the charges contributing to the plasma frequency in silver. This initiates a blue shift of the silver plasmon band with a simultaneous blue shift of the photonic band gap as a result of the change in the silver dielectric function
  • resonance at 450 nm reported in Figure 3b is related to the electron–phonon scattering. This picosecond-scale dynamic is followed by a very weak phonon–phonon scattering. The photonic band gap (around 620 nm) does not show any particular dynamic (not shown here), as expected. The combination of a metal and
  • a dielectric in the photonic device is a key to the voltage-dependent observations, as will be explained later in this manuscript. Upon application of an electrical potential to the device, we observe a blue shift of the entire transmission spectrum, that is, of the photonic band gap as well as the
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Published 06 Oct 2016

Microwave synthesis of high-quality and uniform 4 nm ZnFe2O4 nanocrystals for application in energy storage and nanomagnetics

  • Christian Suchomski,
  • Ben Breitung,
  • Ralf Witte,
  • Michael Knapp,
  • Sondes Bauer,
  • Tilo Baumbach,
  • Christian Reitz and
  • Torsten Brezesinski

Beilstein J. Nanotechnol. 2016, 7, 1350–1360, doi:10.3762/bjnano.7.126

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  • quality of the partially inverted ZFO nanoparticles. This is also supported by the analysis of the optical properties. The Tauc plots shown in Supporting Information File 1, Figure S8 indicate an indirect band gap transition at about 650 nm (≈1.9 eV), which is in accordance with literature values and
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Published 27 Sep 2016

Ammonia gas sensors based on In2O3/PANI hetero-nanofibers operating at room temperature

  • Qingxin Nie,
  • Zengyuan Pang,
  • Hangyi Lu,
  • Yibing Cai and
  • Qufu Wei

Beilstein J. Nanotechnol. 2016, 7, 1312–1321, doi:10.3762/bjnano.7.122

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  • ] and WO3 [12] have been reported. Indium oxide (In2O3) is an n-type semiconductor with a band gap of approximately 3.55–3.75 eV, which has been widely used due to its excellent electrical and optical properties. In2O3 also exhibits sensitivity to various vapors and gases, such as NO2 [13], CO [14], H2
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Published 19 Sep 2016

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

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  • then examined. The morphology of the fibres and the dispersion of nanoparticles in their volume were examined using scanning electron microscopy (SEM). All of the physical properties, which included the band gap width, dielectric constant and refractive index, were tested and plotted against the
  • concentration by weight of the used reinforcing phase, which was as follows: 0%, 4%, 8% and 12% for each type of nanoparticles. The width of the band gap was determined on the basis of the absorption spectra of radiation (UV–vis) and ellipsometry methods. Spectroscopic ellipsometry has been used in order to
  • determines the width of the band gap. The second method allowing one to determine the relationship between the absorption coefficient α and the energy of the electromagnetic waves is using UV–vis spectral analysis of the obtained fibrous layers. In this case, the nanofibres were directly deposited on
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Published 05 Aug 2016

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

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  • including Hf and O vacancies [21]. The motivation of the present work is different from other well-studied luminescent nanocomposites containing TiO2 and ZnO that are investigated around band gap excitation. Here, contrary to the previous two semiconductors, novel optical properties and photocurrent
  • generation are expected from the hybrid material studied in under band gap excitation conditions. Nevertheless, one has to also consider that nanoparticles in contact with the CNT may undergo surface passivation along with corresponding changes in the electron trap states within the band gap [35
  • peak of the CNT gradually overlaps with the band gap absorption edge of the HfO2 nanoparticles. This implies that a possible antenna effect of the CNTs on HfO2 is likely if the material is excited in the deep UV region. The photocurrent measurements further indicate that evacuation of charges from the
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Published 26 Jul 2016

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

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  • absorption for LIOB will require between six and twelve photons with the same polarization to exceed the band-gap energy of water, which is approx. 6.5 eV [34]. LIOB occurs when the optical breakdown threshold, which is in the range of about 1011–1013 W/cm2, is surpassed in the focal region of the laser beam
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Published 16 Jun 2016

Selective photocatalytic reduction of CO2 to methanol in CuO-loaded NaTaO3 nanocubes in isopropanol

  • Tianyu Xiang,
  • Feng Xin,
  • Jingshuai Chen,
  • Yuwen Wang,
  • Xiaohong Yin and
  • Xiao Shao

Beilstein J. Nanotechnol. 2016, 7, 776–783, doi:10.3762/bjnano.7.69

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  • activity was LiTaO3 > NaTaO3 > KTaO3, which was consistent with that of the Eg (band gap) values. However, the highest yield of CO in LiTaO3 was 0.42 μmol/g after 24 h of photoirradiation, which was still far from satisfactory. Ye et al. [16] synthesized a series of noble-metal-loaded NaTaO3 samples to
  • Figure 3a, it can be observed that the main absorption peaks are around 300 nm, which means the powders have an apparent absorption of UV light. The band gap energy (Eg) of each catalyst, prepared with different NaOH concentrations from 1 mol/L to 4 mol/L, can be seen in Figure 3b where the Eg values of
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Published 01 Jun 2016

Microwave solvothermal synthesis and characterization of manganese-doped ZnO nanoparticles

  • Jacek Wojnarowicz,
  • Roman Mukhovskyi,
  • Elzbieta Pietrzykowska,
  • Sylwia Kusnieruk,
  • Jan Mizeracki and
  • Witold Lojkowski

Beilstein J. Nanotechnol. 2016, 7, 721–732, doi:10.3762/bjnano.7.64

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  • oxides semiconductors. Zinc oxide (ZnO) is a II–VI semiconductor characterised by a wide band gap of 3.3 eV and a high exciton binding energy of circa 60 meV [4]. ZnO is used in optoelectronic devices, solar cells, data carriers, light emitting diodes (LEDs), gas sensors, thermoelectric devices
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Published 19 May 2016

Bacteriorhodopsin–ZnO hybrid as a potential sensing element for low-temperature detection of ethanol vapour

  • Saurav Kumar,
  • Sudeshna Bagchi,
  • Senthil Prasad,
  • Anupma Sharma,
  • Ritesh Kumar,
  • Rishemjit Kaur,
  • Jagvir Singh and
  • Amol P. Bhondekar

Beilstein J. Nanotechnol. 2016, 7, 501–510, doi:10.3762/bjnano.7.44

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  • ][24]. The preference of ZnO in applications for the formation of hybrid structures is due to its high band gap (3.39 eV), large excitonic binding energy (60 meV), and high isoelectric point (9.2) [23][25][26][27]. One of the early reported works by Heiland in 1959 demonstrated the use of ZnO as a gas
  • trend in the respective hybrid structures, 362 nm for ZnO-TF/bR and 358 nm for ZnO-NR/bR. The blue shift in the excitonic absorption may be due to the reduction of grain size and improved structural quality of the surface. It is an indication of the increase in the band gap energy as the result of
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Published 04 Apr 2016

Determination of Young’s modulus of Sb2S3 nanowires by in situ resonance and bending methods

  • Liga Jasulaneca,
  • Raimonds Meija,
  • Alexander I. Livshits,
  • Juris Prikulis,
  • Subhajit Biswas,
  • Justin D. Holmes and
  • Donats Erts

Beilstein J. Nanotechnol. 2016, 7, 278–283, doi:10.3762/bjnano.7.25

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  • photosensitivity [3], its large absorption coefficient [4][5] and direct band gap in the visible and near infrared range (1.78–2.5 eV) [6][7][8]. Owing to these properties, Sb2S3 has also been considered as an attractive material for microwave frequency [9], optical recording [10] and photovoltaic [2][11
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Published 19 Feb 2016

Synthesis and applications of carbon nanomaterials for energy generation and storage

  • Marco Notarianni,
  • Jinzhang Liu,
  • Kristy Vernon and
  • Nunzio Motta

Beilstein J. Nanotechnol. 2016, 7, 149–196, doi:10.3762/bjnano.7.17

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  • hexagons around the equatorial plane and exhibits a more oval shape (Figure 4) [26]. The main properties of C60 are [25]: Young’s modulus, ≈14 GPa Electrical resistivity, ≈1014 Ω m Thermal conductivity, ≈0.4 W/mK Band gap, 1.7 eV The other fullerene species show similar properties to C60. Depending on the
  • because it strongly affects the electronic properties of the SWNTs. For a given (n, m) nanotube, if n = m, the nanotube is metallic; in all other cases, the nanotube is semiconducting with the remarkable situation that when (n − m) is a multiple of 3, the nanotube has a very small band gap [45]. It was
  • ], impermeability to gases [69], capability to carry high current densities (a million times higher than copper) [70], anomalous quantum Hall effect (QHE) that appears larger than in other materials [71][72], and zero band gap semiconducting properties with one type of electrons and one type of holes [73] that can
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Published 01 Feb 2016
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