Modeling a multiple-chain emeraldine gas sensor for NH₃ and NO₂ detection

• Hana Sustkova and
• Jan Voves

Beilstein J. Nanotechnol. 2022, 13, 721–729, doi:10.3762/bjnano.13.64

• molecular properties of polyaniline have been studied by quantum mechanical means in [4][8]. The band structure was calculated by Reis et al. [9], together with transmittance, electrical current flow, and charge density. For these calculations, density functional theory (DFT, [10]) based on the generalized

Revealing local structural properties of an atomically thin MoSe₂ surface using optical microscopy

• Lin Pan,
• Peng Miao,
• Anke Horneber,
• Alfred J. Meixner,
• Pierre-Michel Adam and
• Dai Zhang

Beilstein J. Nanotechnol. 2022, 13, 572–581, doi:10.3762/bjnano.13.49

• effects strongly influence the optical and electronic properties of 2D-TMDC materials. Optical second harmonic generation (SHG) spectroscopy has been recently used to study the presence of mid-gap states in the electronic band structure of WS2 flakes, which are induced by sulfur vacancies [14]. In

• defect-induced band bending of the conduction band at K and Q states in few-layer MoS2 [9][10]. All in all, structural irregularities play a crucial role in the modification of the electron band structure in 2D-TMDCs, further ruling their optical and electronic properties. Therefore, the relationship

• the interaction with local dipoles in plasma-treated MoS2 [22]. Additionally, the electronic band structure of MoS2 can be significantly modified after oxygen incorporation into MoS2. The charge transfer from the valence band of partially oxidized MoS2 to the LUMO of R6G can be tuned in resonance with

Zinc oxide nanostructures for fluorescence and Raman signal enhancement: a review

• Ioana Marica,
• Fran Nekvapil,
• Maria Ștefan,
• Cosmin Farcău and
• Alexandra Falamaș

Beilstein J. Nanotechnol. 2022, 13, 472–490, doi:10.3762/bjnano.13.40

• a higher adsorption of analyte molecules, increasing the EF from 106 (before) to 108 (after hydrogenation) [43]. The charge transfer effect was probably increased as well since the hydrogenation introduced lattice defects that could alter the energy band structure of ZnO, promoting charge separation

Theoretical understanding of electronic and mechanical properties of 1T′ transition metal dichalcogenide crystals

• Seyedeh Alieh Kazemi,
• Sadegh Imani Yengejeh,
• Vei Wang,
• William Wen and
• Yun Wang

Beilstein J. Nanotechnol. 2022, 13, 160–171, doi:10.3762/bjnano.13.11

• , the partial crystal orbital Hamilton population (-pCOHP) is analyzed using the LOBSTER program through the partition of the band-structure energy into orbital–pair interactions [47][48]. Results Structural properties The geometrical structures of TMDs in the 1T′ structural polytype are illustrated in

• well-known differences between these two phases is their electronic properties. Using MoS2 as an example, its 1T′ and 2H polytypes are discussed by presenting their DOS and band structure, as illustrated in Figure 5a. There is a bandgap in the 2H polytype, which indicates that it is a semiconductor. On

• indicated in Figure 1. Calculated mechanical properties of 1T′ MoS2, MoSe2, WS2 and WSe2 crystals including (A) the elastic constants, (B) bulk moduli (B), shear moduli (G), Young’s moduli (Y), microhardness (H), and (C) Poisson’s ratio (ν) and B/G ratios. (a) Total and partial DOS and band structure of

Tin dioxide nanomaterial-based photocatalysts for nitrogen oxide oxidation: a review

• Viet Van Pham,
• Hong-Huy Tran,
• Thao Kim Truong and
• Thi Minh Cao

Beilstein J. Nanotechnol. 2022, 13, 96–113, doi:10.3762/bjnano.13.7

• catalytic area, SnO2 is an emerging material for removing contaminants such as organic dyes, phenolic compounds, and volatile organic compounds (VOCs) due to strongly oxidizing properties thanks to flexible energy band structure, rich defects, good chemical, and high thermal stability, and easily controlled

• the band structure. Moreover, the bandgap of SnO2−x self-doped with Sn2+ can be easily determined as follows: A straight line to the x-axis, equaling to the extrapolated value of Ephoton at α = 0, gives the absorption edge energy. This energy parameter corresponds to the bandgap (Eg) of the material

• •O2− radicals played a primary role in the photocatalytic NO oxidation. Additionally, using photoluminescence (PL) spectroscopy, XPS, active species trapping tests, and ESR spectroscopy, the authors studied the photoinduced charge migration and trapping. They proposed the band structure of the SnO2

First-principles study of the structural, optoelectronic and thermophysical properties of the π-SnSe for thermoelectric applications

• Muhammad Atif Sattar,
• Najwa Al Bouzieh,
• Maamar Benkraouda and
• Noureddine Amrane

Beilstein J. Nanotechnol. 2021, 12, 1101–1114, doi:10.3762/bjnano.12.82

• hierarchical architecture [2][11][12] as well as through nanostructuring [13][14][15]), retaining the hole mobility [16][17], and by improving the value of the Seebeck coefficient (by tuning the band structure [18] along with a large conduction (valence) band convergence [19][20], electron energy barrier

• configuration of Sn [5s25p0] and Se [4s24p4] is theoretically helpful, yet the heteropolar bonding is nuanced. The projected electronic band structure of the cubic π-SnSe system is shown in Figure 4. The red, green, and blue colors represent the Sn s, Sn p, and Se p orbitals, respectively. The s states of Sn

• bandgap of π-SnSe is larger than that of α-SnSe which has an indirect bandgap of 0.9 eV [1]. It can be also visualized that the band structure of the π-SnSe phase is distorted as compared to the band structure of the ideal rock-salt SnSe phase (64 atoms) which has a very small bandgap of 0.2 eV [47

Revealing the formation mechanism and band gap tuning of Sb₂S₃ nanoparticles

• Maximilian Joschko,
• Franck Yvan Fotue Wafo,
• Christina Malsi,
• Danilo Kisić,
• Ivana Validžić and
• Christina Graf

Beilstein J. Nanotechnol. 2021, 12, 1021–1033, doi:10.3762/bjnano.12.76

• ][40][41], while others proposed an indirect transition [42][43][44][45]. However, amorphous materials exhibit neither an indirect nor a direct transition as these materials are highly disordered and do not have a band structure based on the Bloch theorem. Nevertheless, the electronic states in

A review of defect engineering, ion implantation, and nanofabrication using the helium ion microscope

• Frances I. Allen

Beilstein J. Nanotechnol. 2021, 12, 633–664, doi:10.3762/bjnano.12.52

• ]. In addition, density functional theory has been used to model the effect of ion-induced defects on the electronic band structure of various 2D transition metal dichalcogenides [26][30][36], and band-excitation Kelvin probe microscopy has been used to probe the resulting changes in the local work

• high levels of disorder in the crystal. Up to this critical dose, it was shown that the valley polarization properties of the material were preserved (indicating that the electronic band structure of the semiconductor was largely unaffected). Only for high levels of disorder introduced into the system

• was the band structure degraded. Based on these results, the authors determined a critical dose for nanostructuring MoS2 below which the optical and valleytronic properties of the material are conserved. In subsequent work, the formation of arrays of optically active defects in monolayer MoS2 was

Properties of graphene deposited on GaN nanowires: influence of nanowire roughness, self-induced nanogating and defects

• Jakub Kierdaszuk,
• Piotr Kaźmierczak,
• Justyna Grzonka,
• Aleksandra Krajewska,
• Aleksandra Przewłoka,
• Wawrzyniec Kaszub,
• Zbigniew R. Zytkiewicz,
• Marta Sobanska,
• Maria Kamińska,
• Andrzej Wysmołek and
• Aneta Drabińska

Beilstein J. Nanotechnol. 2021, 12, 566–577, doi:10.3762/bjnano.12.47

• equal to 1583.5 cm–1 [14]. The sensitivity of the G band energy on the carrier concentration is caused by the presence of a Kohn anomaly near the Γ point in the phonon band structure of graphene [15]. Consequently, the G band energy significantly increases with an increasing concentration of both

On the stability of microwave-fabricated SERS substrates – chemical and morphological considerations

• Limin Wang,
• Aisha Adebola Womiloju,
• Christiane Höppener,
• Ulrich S. Schubert and
• Stephanie Hoeppener

Beilstein J. Nanotechnol. 2021, 12, 541–551, doi:10.3762/bjnano.12.44

• can be found in Supporting Information File 1, Table S1. The observed band structure clearly identifies bands at 1394, 1440, and 1580 cm−1 which are indicative of 4,4’-dimercaptoazobenzene (DMAB), which is formed by an oxidative transformation of 4-ATP on Ag nanoparticle surfaces at higher laser power

Boosting of photocatalytic hydrogen evolution via chlorine doping of polymeric carbon nitride

• Malgorzata Aleksandrzak,
• Michalina Kijaczko,
• Wojciech Kukulka,
• Daria Baranowska,
• Martyna Baca,
• Beata Zielinska and
• Ewa Mijowska

Beilstein J. Nanotechnol. 2021, 12, 473–484, doi:10.3762/bjnano.12.38

• semiconductor polymer, as a metal-free and visible-light-responsive photocatalyst, has attracted dramatically growing attention in the field of visible-light-induced hydrogen evolution reaction (HER). It is characterized by facile synthesis, easy functionalization, attractive electronic band structure, and

Free and partially encapsulated manganese ferrite nanoparticles in multiwall carbon nanotubes

• Saja Al-Khabouri,
• Salim Al-Harthi,
• Toru Maekawa,
• Mohamed E. Elzain,
• Ashraf Al-Hinai,
• Ahmed D. Al-Rawas,
• Abbsher M. Gismelseed,
• Ali A. Yousif and
• Myo Tay Zar Myint

Beilstein J. Nanotechnol. 2020, 11, 1891–1904, doi:10.3762/bjnano.11.170

• , experimentally, bulk MnFe2O4 is known to have semiconductor properties [18]. The spectrum shown in Figure 1e contains a main peak at approx. 5.4 eV and weaker peaks at approx. 9.7 eV and 12.1 eV. By comparing the spectrum with the band structure calculations, the first peak (indicated by an arrow in the spectrum

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