Kondo effects in small-bandgap carbon nanotube quantum dots

• Patryk Florków,
• Damian Krychowski and
• Stanisław Lipiński

Beilstein J. Nanotechnol. 2020, 11, 1873–1890, doi:10.3762/bjnano.11.169

• single-walled carbon nanotube is a hollow cylinder formed of graphene. A CNT can be either metallic or semiconducting, depending on the way graphene is rolled up [37][38]. In the simple “zone folding” picture [39][40], the band structure of CNTs is obtained from the band structure of graphene by imposing

• only by the response of orbital and spin magnetic moments, as in the case of large gaps. They also crucially depend on the value of the bandgap and the gate voltage. Details of the band structure are decisive for the response on the field. The degeneracy recovery lines plotted in the plane of magnetic

• resonances with effective spin, valley, or spin–valley fluctuations, the emergence of an exotic SU(3) Kondo resonance is foreseen even without mixing between shells or valleys, but simply due to the peculiarity of the band structure and a subtle interplay of magnetic field, spin–orbit interaction, and

Unravelling the interfacial interaction in mesoporous SiO₂@nickel phyllosilicate/TiO₂ core–shell nanostructures for photocatalytic activity

• Bridget K. Mutuma,
• Xiluva Mathebula,
• Isaac Nongwe,
• Bonakele P. Mtolo,
• Boitumelo J. Matsoso,
• Rudolph Erasmus,
• Zikhona Tetana and
• Neil J. Coville

Beilstein J. Nanotechnol. 2020, 11, 1834–1846, doi:10.3762/bjnano.11.165

• functionality of nanomaterials greatly influence their photoactivity. UV–vis diffuse reflectance spectroscopy is a useful technique for probing the optoelectronic properties, band structure and molecular energy levels of semiconductors. It gives relevant information on the optical activity of nanomaterials as

Self-standing heterostructured NiC_x-NiFe-NC/biochar as a highly efficient cathode for lithium–oxygen batteries

• Shengyu Jing,
• Xu Gong,
• Shan Ji,
• Linhui Jia,
• Bruno G. Pollet,
• Sheng Yan and
• Huagen Liang

Beilstein J. Nanotechnol. 2020, 11, 1809–1821, doi:10.3762/bjnano.11.163

• ]. The hybridization between the d-orbital of the transition metal and s- and p-orbitals of carbon effectively stretch the d-band structure of the transition metal. This results in a similar d-band of PGMs, which makes these metal carbides promising candidates to replace PGM-based ORR and OER catalysts

• a NiFe-PBA/PP-900 cathode was 1.3 V, which is lower than that of NiFe-PBA/PP-700 (1.5 V). In other words, NiFe-PBA/PP-900 has a better cell performance than NiFe-PBA/PP-700. This improved electrocatalytic activity was probably due to the formation of nickel carbide at 900 °C with an expanded d-band

• structure of nickel, which arised from the synergistic effect between nickel and carbon in NiCx. Figure 6a shows the rate performance of NiFe-PBA/PP-900 at current density values ranging from 0.1 to 0.5 mA·cm−2 within a cell voltage window ranging from 2.0 to 4.5 V. It was observed that, when the current

The influence of an interfacial hBN layer on the fluorescence of an organic molecule

• Christine Brülke,
• Oliver Bauer and
• Moritz M. Sokolowski

Beilstein J. Nanotechnol. 2020, 11, 1663–1684, doi:10.3762/bjnano.11.149

• a disordered phase, while the RT state forms highly ordered domains [44]. This is accompanied by a change in the valence band structure as seen, for example, in UPS [44]. Thus, instead of a multilayer/monolayer effect, the above described differences in the Raman shifts may also be caused by the

Structural and electronic properties of SnO₂ doped with non-metal elements

• Jianyuan Yu,
• Yingeng Wang,
• Yan Huang,
• Xiuwen Wang,
• Jing Guo,
• Jingkai Yang and
• Hongli Zhao

Beilstein J. Nanotechnol. 2020, 11, 1321–1328, doi:10.3762/bjnano.11.116

•  3) are all negative, illustrating that all the doped crystal structures are stable structures. The defect binding energy decreases in the order of B, S, C, N, and F. The SnO2 doped with F has the lowest binding energy, which makes it the most stable structure. Band structure and density of states

• conduction band. The electronic structure including the energy band structure, total density of states and partial wave state density of the doped system are shown in Figure 2. For SnO2, the Fermi energy level is at the top of the valence band, indicating that the conductivity of SnO2 is low. The conduction

• conduction band of SnO2 crystal, and SnO2 becomes a conductor. The energy band structure of SnO2 doped with C and N shows that the Fermi level crosses the impurity level and the conductivity of SnO2 semiconductor is enhanced. To sum up, it can be seen that doping with F can enhance the conductivity of SnO2

Hybridization vs decoupling: influence of an h-BN interlayer on the physical properties of a lander-type molecule on Ni(111)

• Maximilian Schaal,
• Takumi Aihara,
• Marco Gruenewald,
• Felix Otto,
• Jari Domke,
• Roman Forker,
• Hiroyuki Yoshida and
• Torsten Fritz

Beilstein J. Nanotechnol. 2020, 11, 1168–1177, doi:10.3762/bjnano.11.101

• -temperature scanning tunneling microscopy. Finally, the investigation of the valence band structure by ultraviolet photoelectron spectroscopy shows that the low work function of h-BN/Ni(111) further decreases after the DBP deposition. For this reason, the h-BN-passivated Ni(111) surface may serve as potential

• as clusters of molecules on top of the first DBP layer. The fast Fourier transform (FFT) of that STM image resembles the LEED simulation of the molecular lattice (considering eight symmetry equivalent domains only), which supports our structural model. Valence band structure and work function change

• is consistent with vacuum level alignment (see section “Valence band structure and work function change” above). The origin of the more pronounced broadening as well as the asymmetric line shape [45] of the C 1s level in the case of DBP on bare Ni(111) may stem from a variety of different adsorption

Monolayers of MoS₂ on Ag(111) as decoupling layers for organic molecules: resolution of electronic and vibronic states of TCNQ

• Asieh Yousofnejad,
• Gaël Reecht,
• Nils Krane,
• Christian Lotze and
• Katharina J. Franke

Beilstein J. Nanotechnol. 2020, 11, 1062–1071, doi:10.3762/bjnano.11.91

• conduction bands between the MoS2 bands on Ag and Au. In a very simple interpretation, this agrees with the lower work function of Ag than that of Au. A down-shift of the conduction band structure by approx. 280 meV has been observed by photoemission of WS2 on Au(111) and Ag(111) [33]. Angle-resolved

Excitonic and electronic transitions in Me–Sb₂Se₃ structures

• Nicolae N. Syrbu,
• Victor V. Zalamai,
• Ivan G. Stamov and
• Stepan I. Beril

Beilstein J. Nanotechnol. 2020, 11, 1045–1053, doi:10.3762/bjnano.11.89

• –orbit interaction (Δso = 35 meV) and the crystal field (Δcf = 13 meV) were estimated in the Brillouin zone center. The energy splitting between the bands V3–V4 was 191 meV. The identified features were discussed based on both the theoretically calculated energy band structure and the excitonic band

• triselenide; band structure; excitons; optical spectroscopy; reflection and absorption spectra; Introduction Antimony selenide (Sb2Se3) is an inorganic semiconductor compound with interesting photoelectric properties. This material has a high absorption coefficient (≈105 cm−1) in the region of maximum solar

• ][15]. In order to use Sb2Se3 to build high-performance devices it is necessary to study its crystalline nanostructure in terms of band structure and optical and optoelectronic properties, especially in the bandgap region in which ambiguous and contradictory results have been obtained. For example, the

A new photodetector structure based on graphene nanomeshes: an ab initio study

• Babak Sakkaki,
• Hassan Rasooli Saghai,
• Ghafar Darvish and
• Mehdi Khatir

Beilstein J. Nanotechnol. 2020, 11, 1036–1044, doi:10.3762/bjnano.11.88

• electronic and optical characteristics of various GNM structures. To investigate the device-level properties of GNMs, their current–voltage characteristics are explored by DFT-based tight-binding (DFTB) in combination with non-equilibrium Green’s function (NEGF) methods. Band structure analysis shows that

• particular, photodetectors based on graphene will have a large dark current due to the conductivity of graphene even without incident photons [2]. An energy gap in the band structure of graphene can be created using quantum confinement effects via creating graphene nanoribbons (GNRs) with a width of

Band tail state related photoluminescence and photoresponse of ZnMgO solid solution nanostructured films

• Vadim Morari,
• Aida Pantazi,
• Nicolai Curmei,
• Vitalie Postolache,
• Emil V. Rusu,
• Marius Enachescu,
• Ion M. Tiginyanu and
• Veaceslav V. Ursaki

Beilstein J. Nanotechnol. 2020, 11, 899–910, doi:10.3762/bjnano.11.75

• random local-potential fluctuations occur in highly doped and compensated semiconductors [39] and solid solutions [40] due to the microscopic inhomogeneity caused by impurity distribution in the first case and composition distribution in the second case. This spatially fluctuating band structure results

Hexagonal boron nitride: a review of the emerging material platform for single-photon sources and the spin–photon interface

• Stefania Castelletto,
• Faraz A. Inam,
• Shin-ichiro Sato and
• Alberto Boretti

Beilstein J. Nanotechnol. 2020, 11, 740–769, doi:10.3762/bjnano.11.61

• indirect bandgaps. Bandgap energy values largely varying from 3.6 eV to 7.1 eV have been reported in the literature [84][85][86]. Theoretical calculations for the h-BN band structure also show significant differences in the eV values. Some density functional theory (DFT) in the local-density-approximation

DFT calculations of the structure and stability of copper clusters on MoS₂

• Cara-Lena Nies and
• Michael Nolan

Beilstein J. Nanotechnol. 2020, 11, 391–406, doi:10.3762/bjnano.11.30

• electrons. In general, the atoms prefer to adsorb above a Mo atom, however Sc, Ti and Mn prefer a hollow site inside the Mo–S hexagon. Overall, it was concluded that the band structure and magnetic properties of 2D MoS2 can be modified by adsorbing different transition metals [26]. Li et al. [29] and

Nonequilibrium Kondo effect in a graphene-coupled quantum dot in the presence of a magnetic field

• Levente Máthé and
• Ioan Grosu

Beilstein J. Nanotechnol. 2020, 11, 225–239, doi:10.3762/bjnano.11.17

• points the energy dispersion of quasiparticles in graphene is linear in momentum. This linear band structure is called a Dirac cone, and it is at the basis of many interesting physical phenomena such as the ’chiral’ quantum Hall effect [51], the Klein tunneling effect [50] and the Aharonov–Bohm effect

• method [16]: where ε0 = εd − μ. We observe that TK only depends on U and is independent of D for metallic contacts. For graphene contacts, is regulated by U and also by D. The presence of D in is due to the fact that it determines the band structure of graphene. Therefore, at the particle–hole symmetry

Semitransparent Sb₂S₃ thin film solar cells by ultrasonic spray pyrolysis for use in solar windows

• Jako S. Eensalu,
• Atanas Katerski,
• Erki Kärber,
• Lothar Weinhardt,
• Monika Blum,
• Clemens Heske,
• Wanli Yang,
• Ilona Oja Acik and
• Malle Krunks

Beilstein J. Nanotechnol. 2019, 10, 2396–2409, doi:10.3762/bjnano.10.230

• , is found at 151 eV and ascribed to Sb 5s-derived states by comparison with band structure and density of states calculations [50]. Lastly, transitions from the upper valence band of Sb2S3 can be found centered at around 156 eV. These transitions were identified in line with atom-decomposed density of

Improved adsorption and degradation performance by S-doping of (001)-TiO₂

• Xiao-Yu Sun,
• Xian Zhang,
• Xiao Sun,
• Ni-Xian Qian,
• Min Wang and
• Yong-Qing Ma

Beilstein J. Nanotechnol. 2019, 10, 2116–2127, doi:10.3762/bjnano.10.206

• further investigation. These include the differences between lightly and heavily doped TiO2 as well as the effects of S-doping on the crystal structure, the energy band structure and the chemical states of Ti and O. In this work, (001)-TiO2 nanoparticles (NPs) were first prepared, then S-doping was

Improvement of the thermoelectric properties of a MoO₃ monolayer through oxygen vacancies

• Wenwen Zheng,
• Wei Cao,
• Ziyu Wang,
• Huixiong Deng,
• Jing Shi and
• Rui Xiong

Beilstein J. Nanotechnol. 2019, 10, 2031–2038, doi:10.3762/bjnano.10.199

• [21][22] to obtain a more accurate band structure. The vacuum distance is set to 15 Å to avoid interactions between the MoO3 monolayer and its periodic images. A plane-wave basis set with a cutoff of 520 eV is chosen, and the k-mesh is tested to be 10 × 10 × 1 for the purpose of convergence. Based on

• × 3 × 1 supercell): top and side views. (b) The electronic band structure and (c) the phonon dispersion of the MoO3 monolayer along the high-symmetry path. (d) The lattice thermal conductivity, κph, of the MoO3 monolayer along different directions as a function of temperature. Transport and

• atoms, that are connected to different molybdenum atoms, as indicated by different colors in Figure 1a. The relaxed lattice constants of the MoO3 monolayer are a = 3.68 Å and b = 3.93 Å, which are similar to the bulk experimental data of 3.70 and 3.96 Å [30]. In Figure 1b, we give the electronic band

Charge-transfer interactions between fullerenes and a mesoporous tetrathiafulvalene-based metal–organic framework

• Manuel Souto,
• Joaquín Calbo,
• Samuel Mañas-Valero,
• Aron Walsh and
• Guillermo Mínguez Espallargas

Beilstein J. Nanotechnol. 2019, 10, 1883–1893, doi:10.3762/bjnano.10.183

• density (Tkatchenko–Scheffler method) [59]. Electronic structure calculations were performed for band structure analysis using the hybrid HSE06 functional [60] and tier-1 basis set. Energy reference was set to vacuum according to the protocol reported by Butler and co-workers [61]. Crystal structures

Fabrication and characterization of Si_1−xGe_x nanocrystals in as-grown and annealed structures: a comparative study

• Muhammad Taha Sultan,
• Adrian Valentin Maraloiu,
• Ionel Stavarache,
• Jón Tómas Gudmundsson,
• Andrei Manolescu,
• Valentin Serban Teodorescu,
• Magdalena Lidia Ciurea and
• Halldór Gudfinnur Svavarsson

Beilstein J. Nanotechnol. 2019, 10, 1873–1882, doi:10.3762/bjnano.10.182

• possible. An increased number of dangling bonds increases the number of localized states in the band structure along with an increase in non-radiative centers (Pb) [48][49]. This results in a broadening of the energy width of localized states with annealing temperature, resulting in bandgap alteration

Giant magnetoresistance ratio in a current-perpendicular-to-plane spin valve based on an inverse Heusler alloy Ti₂NiAl

• Yu Feng,
• Zhou Cui,
• Bo Wu,
• Jianwei Li,
• Hongkuan Yuan and
• Hong Chen

Beilstein J. Nanotechnol. 2019, 10, 1658–1665, doi:10.3762/bjnano.10.161

• metallicity, while minority spin bands possess an energy gap around the Fermi level. Such a novel band structure results in a theoretical 100% spin polarization, which is one of the most crucial parameters for CPP-SV according to the Valet–Fert model [5]. As one of the subfamilies of Heusler alloys

Direct observation of oxygen-vacancy formation and structural changes in Bi₂WO₆ nanoflakes induced by electron irradiation

• Hong-long Shi,
• Bin Zou,
• Zi-an Li,
• Min-ting Luo and
• Wen-zhong Wang

Beilstein J. Nanotechnol. 2019, 10, 1434–1442, doi:10.3762/bjnano.10.141

• that self-adapt to keep the balance of space charges. Previous reports [14][15] have indicated that defects in Bi2WO6 affect its physical properties because defects can modify the band structure and electron–hole pairs [16][17]. Oxygen vacancies in the insulating layers of Bi2WO6 are defects that can

BiOCl/TiO₂/diatomite composites with enhanced visible-light photocatalytic activity for the degradation of rhodamine B

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

Beilstein J. Nanotechnol. 2019, 10, 1412–1422, doi:10.3762/bjnano.10.139

• species [41]. The generation of particular active species in the photocatalytic process varies with the type of catalyst (mainly the energy band structure) [42]. KI, IPA and 1,4-benzoquinone (BQ) were used as scavengers for pores (h+), hydroxyl radicals (OH) and superoxide radicals (O2−), respectively, to

• good cyclic ability and stability. Photocatalytic mechanism analysis In order to reveal the photocatalytic mechanism, we observe the optical, photochemical and electrochemical properties to study the energy band structure and carrier migration pathway of BTD. Figure 8a presents the UV–vis diffuse

• lower than ordinary TiO2 (3.18 eV). The Eg of BTD decreases, obviously due to the formation of heterojunction structures in the composite, which is beneficial to visible light response. To further study the band structure of the composites, the Mott–Schottky curves were calculated and are plotted in

Electronic and magnetic properties of doped black phosphorene with concentration dependence

• Ke Wang,
• Hai Wang,
• Min Zhang,
• Yan Liu and
• Wei Zhao

Beilstein J. Nanotechnol. 2019, 10, 993–1001, doi:10.3762/bjnano.10.100

• supercell size due to decreasing deformation and dopant content. In the following, we discuss the magnetic and electronic properties of the stable doped phosphorenes induced by the deformation and impurity concentration. Band structure without spin polarization Before investigating the magnetic properties

• -plane size of the supercell increases and the impurity concentration decreases, the 3p orbit–spin splitting becomes more and more obvious indicating the increased magnetic moment, while the spin distribution changes only little. Electronic properties Band structure with spin polarization We have

• of the supercell increases to 5 × 5, there is a gap of ca. 0.22 eV between the spin-up and spin-down energy bands near the Fermi level in the band structure of S-doped phosphorene, revealing a magnetic semimetal. Si-doped phosphorene also exhibits a semi-metallic state. The opened bandgap may be

Synthesis of novel C-doped g-C₃N₄ nanosheets coupled with CdIn₂S₄ for enhanced photocatalytic hydrogen evolution

• Jingshuai Chen,
• Chang-Jie Mao,
• Helin Niu and
• Ji-Ming Song

Beilstein J. Nanotechnol. 2019, 10, 912–921, doi:10.3762/bjnano.10.92

• metal-free organic catalysts with visible-light response, has been extensively used in pollutant elimination, hydrogen production and photoreduction of CO2 because of its facile fabrication, superior physicochemical stability, appropriate energy band structure, and low cost [7][8][9]. Nevertheless, the

• photocatalytic H2 formation over different samples without incorporation of Pt as the co-catalyst. (b) H2 formation rates of different samples. Cycling study of photocatalytic H2 formation over CISCCN3. Transient photocurrent response of g-C3N4, CCN and CISCCN3 under visible-light irradiation. (a) Band structure

Electronic properties of several two dimensional halides from ab initio calculations

• Mohamed Barhoumi,
• Ali Abboud,
• Lamjed Debbichi,
• Moncef Said,
• Torbjörn Björkman,
• Dario Rocca and
• Sébastien Lebègue

Beilstein J. Nanotechnol. 2019, 10, 823–832, doi:10.3762/bjnano.10.82

• electronic band structures in Figure 9. AcOCl is found to have an indirect bandgap with a value of 6.1 eV with HSE, with the VBM along the S–Y line and the CBM located at the Y point. Next to the band structure of AcOCl, we present the electronic bandstructure of AlOCl. Our results indicate that this

• structures of the monolayers : BiOI, LaOI, ScOI, and YOI, using HSE functional. The Fermi level is set to 0 eV. Evolution of the electronic band structure of AcOBr, BaFBr, BiOBr, CaFBr, CrOF, GaOF, InOF, and LaOF single layers as a function of applied electric field. Calculations are performed with PBE. The

• top of the valence band (red) and bottom of conduction band (blue) are indicated. The Fermi level is set to 0 eV. Evolution of the electronic band structure of: AcOCl, AlOCl, BaFCl, BiOCl, BiOI, LaOI, ScOI, and YOI single layer as a function of applied electric field. Calculations are performed with

A carrier velocity model for electrical detection of gas molecules

• Ali Hosseingholi Pourasl,
• Sharifah Hafizah Syed Ariffin,
• Mohammad Taghi Ahmadi,
• Razali Ismail and
• Niayesh Gharaei

Beilstein J. Nanotechnol. 2019, 10, 644–653, doi:10.3762/bjnano.10.64

• the presence of the gas molecules. Furthermore, the I–V characteristics and energy band structure of the AGNR sensor are simulated using first principle calculations to investigate the gas adsorption effects on these properties. To ensure the accuracy of the proposed model, the I–V characteristics of

• path forward to overcome the constraints of experimental approaches. The adsorption of gas molecules can modulate different electrical and physical properties of the GNRs, such as density of states (DOS), carrier concentration, carrier velocity, I–V characteristics, and energy band structure. On the

• sensors are used to develop a new gas sensor model based on the carrier velocity and I–V characteristics. In addition, a first principle simulation study is employed for the band structure analysis, to calculate the charge transfer, and to evaluate the proposed models. For the sensor structure, an