Computational exploration of two-dimensional silicon diarsenide and germanium arsenide for photovoltaic applications

• Sri Kasi Matta,
• Chunmei Zhang,
• Yalong Jiao,
• Anthony O'Mullane and
• Aijun Du

Beilstein J. Nanotechnol. 2018, 9, 1247–1253, doi:10.3762/bjnano.9.116

• –correlation functional [13]. A Monkhorst–Pack k-points grid [14] of 9 × 3 × 2 and 9 × 3 × 1 was used for sampling the first Brillouin zone for bulk and monolayer for geometry optimizations. Both bulk and monolayer systems are set for relaxing until residual force and energy converged to 0.005 eV/Å and 10−7eV

• , respectively. To study 2D monolayer systems under periodic boundary conditions, a vacuum layer of about 15 Å was introduced to minimize the spurious interaction between neighboring layers. The electronic band structure is predicted through hybrid density functional theory based on the Heyd–Scuseria–Ernzerhof

• bulk equivalent of the same material”, Ef: where, E2D and E3D are the energies of the monolayer and the bulk material, respectively. n2D and n3D are the number of atoms present in the unit cells considered for the calculations [18][19][20]. The optical properties are evaluated by determining the

Heterostuctures of 4-(chloromethyl)phenyltrichlorosilane and 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine prepared on Si(111) using particle lithography: Nanoscale characterization of the main steps of nanopatterning

• Phillip C. Chambers and
• Jayne C. Garno

Beilstein J. Nanotechnol. 2018, 9, 1211–1219, doi:10.3762/bjnano.9.112

• rinsed from the sample. The uniform color contrast observed in the phase image (Figure 2d) indicates that the nanoholes do not contain OTS. The approximate surface coverage of the OTS film measured 97%. The average thickness of the OTS monolayer was measured to be 0.7 nm. The measurements indicate

• submonolayer surface coverage relative to the ideal height (2.6 nm) of a densely packed OTS monolayer [25][41]. The nanoholes within OTS that were generated with particle lithography will serve as sites for further reactions with CMPS and H2TPyP to produce multicomponent nanostructures. Methyl-terminated OTS

An implementation of spin–orbit coupling for band structure calculations with Gaussian basis sets: Two-dimensional topological crystals of Sb and Bi

• Sahar Pakdel,
• Mahdi Pourfath and
• J. J. Palacios

Beilstein J. Nanotechnol. 2018, 9, 1015–1023, doi:10.3762/bjnano.9.94

• all relevant band structure variations induced by SOC. In this work, the non-relativistic or scalar-relativistic Kohn–Sham Hamiltonian is obtained from the CRYSTAL code and the SOC term is added a posteriori. As an example, we apply this method to the Bi(111) monolayer, a paradigmatic 2D topological

• , we have chosen to apply our implementation to Sb and Bi, which are prototypical topological materials where SOC plays a crucial role. Despite being elemental, they present a broad range of behaviors. While bulk Bi is a trivial semimetal, a Bi(111) monolayer is a 2D topological insulator (TI) [27]. Sb

• few-layers in the (111) direction, typically for more than ≈7 layers, behave as a 3D topological semimetal, while the Sb(111) monolayer is a trivial indirect-gap semiconductor. In order for our SOC implementation to be of practical use, it should capture these trivial/non-trivial topological

Electro-optical interfacial effects on a graphene/π-conjugated organic semiconductor hybrid system

• Karolline A. S. Araujo,
• Luiz A. Cury,
• Matheus J. S. Matos,
• Thales F. D. Fernandes,
• Luiz G. Cançado and
• Bernardo R. A. Neves

Beilstein J. Nanotechnol. 2018, 9, 963–974, doi:10.3762/bjnano.9.90

• probe microscopy, optical spectroscopy (photoluminescence and Raman) and ab initio calculations. The graphene/RA interaction induces the formation of a well-organized π-conjugated self-assembled monolayer (SAM) at the interface. Such structural organization leads to the high optical emission efficiency

• of the RA SAM, even at room temperature. Additionally, photo-assisted electrical force microscopy, photo-assisted scanning Kelvin probe microscopy and Raman spectroscopy indicate a RA-induced graphene doping and photo-charge generation. Finally, the optical excitation of the RA monolayer generates

• interfacial effects. Scanning probe microscopy (SPM) and Raman scattering experiments, along with first-principles calculations, reveal the presence of a highly ordered RA self-assembled monolayer atop graphene and graphite. The electro-optical characterization of the hybrid system discloses interfacial

Scanning speed phenomenon in contact-resonance atomic force microscopy

• Christopher C. Glover,
• Jason P. Killgore and
• Ryan C. Tung

Beilstein J. Nanotechnol. 2018, 9, 945–952, doi:10.3762/bjnano.9.87

• , humidity, and loading conditions [17][26][28][29][30][31][32]. Researchers using molecular dynamic (MD) simulations have also found that “at the monolayer coverage, water forms a 2-D H-bonded network in an epitaxial relationship with the mica lattice” [17]. The first complete layer of water is thought to

Comparative study of antibacterial properties of polystyrene films with TiO_x and Cu nanoparticles fabricated using cluster beam technique

• Vladimir N. Popok,
• Cesarino M. Jeppesen,
• Peter Fojan,
• Anna Kuzminova,
• Jan Hanuš and
• Ondřej Kylián

Beilstein J. Nanotechnol. 2018, 9, 861–869, doi:10.3762/bjnano.9.80

• of the NP embedding. For the antibacterial tests, the samples with higher surface cluster coverage (slightly more than one monolayer of particles) are used. A very similar tendency for immersion is found for Ti NPs on PS. Therefore, the AFM images are not presented. The AFM measurements also show

Valley-selective directional emission from a transition-metal dichalcogenide monolayer mediated by a plasmonic nanoantenna

• Haitao Chen,
• Mingkai Liu,
• Lei Xu and
• Dragomir N. Neshev

Beilstein J. Nanotechnol. 2018, 9, 780–788, doi:10.3762/bjnano.9.71

• physical phenomena and great potential applications in valleytronics. Results: Here, we propose a TMDC–nanoantenna system that could effectively enhance and direct emission from the two valleys in TMDCs into diametrically opposite directions. By mimicking the emission from each valley of the monolayer of

• polarization; Introduction The inversion-symmetry breaking and quantum confinement in monolayer TMDCs offer unprecedented opportunities to explore valley-based physics and applications [1][2][3]. The valley pseudospin is associated with the degenerate energy extrema in momentum space [3]. In monolayer TMDCs

• [6][7][8][9][10]. In particular, monolayer TMDCs with direct bandgap at the K and K′ points [11] make it possible to control the valley degree freedom entirely optically. Optical pumping of excitons of a specific valley polarization has been demonstrated by polarization-resolved photoluminescence (PL

Synthesis and characterization of two new TiO₂-containing benzothiazole-based imine composites for organic device applications

• Anna Różycka,
• Agnieszka Iwan,
• Krzysztof Artur Bogdanowicz,
• Michal Filapek,
• Natalia Górska,
• Damian Pociecha,
• Marek Malinowski,
• Patryk Fryń,
• Agnieszka Hreniak,
• Jakub Rysz,
• Paweł Dąbczyński and
• Monika Marzec

Beilstein J. Nanotechnol. 2018, 9, 721–739, doi:10.3762/bjnano.9.67

• isotherms are typical for non-porous or macroporous materials, for which unrestricted multilayer adsorption can occurs. In the isotherm, the characteristic bond (the knee) was found at low pressure, indicating the point at which the creation of a monolayer was completed. On the other hand, type IV is

The effect of atmospheric doping on pressure-dependent Raman scattering in supported graphene

• Egor A. Kolesov,
• Mikhail S. Tivanov,
• Olga V. Korolik,
• Olesya O. Kapitanova,
• Xiao Fu,
• Hak Dong Cho,
• Tae Won Kang and
• Gennady N Panin

Beilstein J. Nanotechnol. 2018, 9, 704–710, doi:10.3762/bjnano.9.65

• . Results and Discussion Pressure-dependent Raman measurements Raman spectra of graphene on various substrates under atmospheric pressure are presented in Figure 1. Monolayer and bilayer graphene were identified by 2D peak approximations with one and four Lorentz functions, respectively, together with the

• 2D peak full-width at half-maximums (FWHMs). The I2D/IG intensity ratio shows values of up to 1.5 for the monolayer and about 0.9 for bilayer graphene (the low I2D/IG values can be explained by adsorption doping [9] and electrostatic doping effects [16], as analyzed throughout the article). Comparing

• -controlled box (pressure ranged from 1000 to about 5 × 10−5 mbar). A laser power of 2 mW was used, and the laser spot diameter was about 1.5 µm. Pressure-dependent measurements were carried out in a typical graphene monolayer and a bilayer low-defect region. Raman spectra of graphene on various substrates

Facile phase transfer of gold nanorods and nanospheres stabilized with block copolymers

• Yaroslav I. Derikov,
• Georgiy A. Shandryuk,
• Raisa V. Talroze,
• Alexander A. Ezhov and
• Yaroslav V. Kudryavtsev

Beilstein J. Nanotechnol. 2018, 9, 616–627, doi:10.3762/bjnano.9.58

• maximum is situated between the peaks of two model spectra, we can conclude that some CTAB is present at the nanorod surface but its quantity is not enough to form a uniform bilayer. Presumably, the bilayer is rarefied near the nanorod ends. In nonpolar organosols, CTAB should form a ca. 2 nm monolayer at

Sensing behavior of flower-shaped MoS₂ nanoflakes: case study with methanol and xylene

• Maryam Barzegar,
• Masoud Berahman and
• Azam Iraji zad

Beilstein J. Nanotechnol. 2018, 9, 608–615, doi:10.3762/bjnano.9.57

• the testing period. The chemoresistance response is defined as (Rair – Rgas)/Rair where Rair and Rgas are the resistance in N2 and the mixed gases in different concentrations, respectively. Simulation A super-cell containing 25 primitive unit cells of monolayer MoS2 was considered as the pristine

• differences, we performed a simulation study on the pristine monolayer and similar surface with sulfur vacancy of MoS2 in the presence of xylene and methanol molecules. Xylene shows almost no interaction with pristine MoS2 while a van der Waals interaction happens in the case of sulfur vacancy, which leads to

Single-step process to improve the mechanical properties of carbon nanotube yarn

• Maria Cecilia Evora,
• Xinyi Lu,
• Nitilaksha Hiremath,
• Nam-Goo Kang,
• Kunlun Hong,
• Roberto Uribe,
• Gajanan Bhat and
• Jimmy Mays

Beilstein J. Nanotechnol. 2018, 9, 545–554, doi:10.3762/bjnano.9.52

• only present in monolayer graphene, but also in carbon structures that have turbostratic graphite (TGr) as part of their components, such as MWNTs. This can be confirmed by the Raman spectra presented in Figure 2. Both structures, monolayer and TGr, are represented as Lorentzian peaks, however, TGr has

Wafer-scale bioactive substrate patterning by chemical lift-off lithography

• Chong-You Chen,
• Chang-Ming Wang,
• Hsiang-Hua Li,
• Hong-Hseng Chan and
• Wei-Ssu Liao

Beilstein J. Nanotechnol. 2018, 9, 311–320, doi:10.3762/bjnano.9.31

• biological species recognition with minimum nonspecific attachment. Herein, a straightforward approach utilizing chemical lift-off lithography to create a diluted self-assembled monolayer matrix for anchoring diverse biological probes is introduced. The strategy encompasses convenient operation, well-tunable

• pattern feature and size, large-area fabrication, high resolution and fidelity control, and the ability to functionalize versatile bioarrays. With the interface-contact-induced reaction, a preformed alkanethiol self-assembled monolayer on a Au surface is ruptured and a unique defect-rich diluted matrix is

• lift-off lithography; patterning; self-assembled monolayer; Introduction Patterning on the micro- to nanoscale plays a key role in modern scientific and engineering research fields. Particularly, the creation of bioactive surfaces with well-defined geometries has drawn lots of attention due to its

Review: Electrostatically actuated nanobeam-based nanoelectromechanical switches – materials solutions and operational conditions

• Liga Jasulaneca,
• Jelena Kosmaca,
• Raimonds Meija,
• Jana Andzane and
• Donats Erts

Beilstein J. Nanotechnol. 2018, 9, 271–300, doi:10.3762/bjnano.9.29

• mechanical strain [124][125], their electrical breakdown and mass loss caused by field evaporation [126]. Graphene: For fabricating NEM switches, monolayer [24][25][26][27] as well as few-layer [28][29][30][31] graphene materials are used. The mechanical properties are decisive for selecting the number of

Dopant-stimulated growth of GaN nanotube-like nanostructures on Si(111) by molecular beam epitaxy

• Alexey D. Bolshakov,
• Alexey M. Mozharov,
• Georgiy A. Sapunov,
• Igor V. Shtrom,
• Nickolay V. Sibirev,
• Vladimir V. Fedorov,
• Evgeniy V. Ubyivovk,
• Maria Tchernycheva,
• George E. Cirlin and
• Ivan S. Mukhin

Beilstein J. Nanotechnol. 2018, 9, 146–154, doi:10.3762/bjnano.9.17

• flux (species/nm2s). Putting all expressions above together, we arrive at: From another point of view, the lateral growth of a new monolayer on the top facet relates to direct impingement and diffusion flux from the sidewalls and from the hollow part (). Therefore, another material balance equation

Electron-driven and thermal chemistry during water-assisted purification of platinum nanomaterials generated by electron beam induced deposition

• Ziyan Warneke,
• Markus Rohdenburg,
• Jonas Warneke,
• Janina Kopyra and
• Petra Swiderek

Beilstein J. Nanotechnol. 2018, 9, 77–90, doi:10.3762/bjnano.9.10

• desorbed from the surface during dosing of H2O and during subsequent or simultaneous electron exposure. Also, the effect of annealing was investigated. In a first experiment (Figure 5), a 30 monolayer film of MeCpPtMe3 was partially degraded by electron irradiation until ESD of CH4 had decreased to about

• diameter of 0.96 nm of an MeCpPtMe3 molecule [33] and considering that condensed precursor layers lose organic material and densify during degradation, a 30 monolayer condensed precursor layer would yield a deposit that is significantly thinner than such a typical FEBID deposit. To mimic a thick deposit

• , 30 monolayer films of MeCpPtMe3 were thus repeatedly deposited and exposed to electron irradiation at E0 varying between 19 eV and 31 eV without intermittent sputter cleaning. Irradiation was performed for each deposition cycle until the formation of volatile CH4 had ceased. Remaining intact

Transition from silicene monolayer to thin Si films on Ag(111): comparison between experimental data and Monte Carlo simulation

• Alberto Curcella,
• Romain Bernard,
• Yves Borensztein,
• Silvia Pandolfi and
• Geoffroy Prévot

Beilstein J. Nanotechnol. 2018, 9, 48–56, doi:10.3762/bjnano.9.7

• easy synthesis, Si/Ag(111) monolayers have been intensively studied [3][4][5][6]. It has been shown that several monolayer structures can be formed, depending on the substrate temperature [7]. All of them probably correspond to a buckled honeycomb structure for Si atoms. For example, a buckling of 0.77

• , the coverage θ has been calibrated from the breaks observed in the evolution of ISi that were attributed to the completion of a silicene monolayer. Here, one monolayer (ML) is referred to the honeycomb silicene plane, whose density is 15.7 atom·nm−2. This also corresponds to the atomic density of a Si

• monolayer. On the contrary, the most intense spots on their LEED diagram were the substrate spots. From that, they concluded to an imperfect wetting of the 10 ML film. Coming back to the present results, our LEED diagram obtained after growth at T = 505 K shows results quite different from the 473 K ones

A robust AFM-based method for locally measuring the elasticity of samples

• Alexandre Bubendorf,
• Stefan Walheim,
• Thomas Schimmel and
• Ernst Meyer

Beilstein J. Nanotechnol. 2018, 9, 1–10, doi:10.3762/bjnano.9.1

• -density polyethylene) and a self-assembled monolayer of 1H,1H,2H,2H-perfluorodecyltrichlorosilane (FDTS) on a silicon oxide substrate perforated with circular holes prepared by polymer blend lithography. For all samples the relation was evidenced by recording Δf1, Δf2 and FN as a function of the Z

• first flexural modes of the cantilever in contact were excited with the amplitudes A1 = 22 mV and A2 = 5 mV for all samples. Samples and measurement conditions Three different polymers (polystyrene (PS), polypropylene (PP) and linear low-density polyethylene (LLDPE)) and a self-assembled monolayer (SAM

• of the Young’s modulus of the FDTS monolayer. Effect of tip functionalization on the SiOx elasticity peak of the SAM sample The proximity of the peaks of FDTS and SiOx holes can be explained by the fact that during scanning, some material of FDTS has gathered around the tip, so that the relatively

Electro-optical characteristics of a liquid crystal cell with graphene electrodes

• Nune H. Hakobyan,
• Hakob L. Margaryan,
• Valeri K. Abrahamyan,
• Vladimir M. Aroutiounian,
• Arpi S. Dilanchian Gharghani,
• Amalya B. Kostanyan,
• Timothy D. Wilkinson and
• Nelson Tabirian

Beilstein J. Nanotechnol. 2017, 8, 2802–2806, doi:10.3762/bjnano.8.279

• . Results and Discussion Synthesis of graphene films The graphene was obtained by a chemical vapor deposition (CVD) process. Details of synthesis and extensive characterization of the CVD graphene can be found in prior works [13][14]. The monolayer graphene film was then transferred from the Cu foil to a

Ab initio study of adsorption and diffusion of lithium on transition metal dichalcogenide monolayers

• Xiaoli Sun and
• Zhiguo Wang

Beilstein J. Nanotechnol. 2017, 8, 2711–2718, doi:10.3762/bjnano.8.270

• , and each X atom is connected to three nearest M atoms with ionic M–X bonds. The side and cross-views of the ball and stick models of the MX2 monolayer are shown in Figure 1. The M atoms are located at the lattice positions of a hexagonal close-packed structure with a trigonal symmetry in the 2H-MX2

• hollow site (H) and the top position above the M atom (T) for Li to be adsorbed on the 2H- and 1T-MX2 monolayers [18]. Four adsorption sites (T1, T2, H1, and H2) are considered for Li adsorption onto the 1T'-MX2 monolayer, as shown in Figure 3c. To analyse the stability of Li adsorbed on the MX2

• monolayers, the adsorption energy, Ead(Li), is calculated using Equation 1: where EMX2+Li and EMX2 are the total energy of the MX2 monolayer with and without Li adsorption, respectively. ELi is the energy of a Li atom in bulk material. The calculated adsorption energy of Li on the stable phase of the MX2

L-Lysine-grafted graphene oxide as an effective adsorbent for the removal of methylene blue and metal ions

• Yan Yan,
• Jie Li,
• Fangbei Kong,
• Kuankuan Jia,
• Shiyu He and
• Baorong Wang

Beilstein J. Nanotechnol. 2017, 8, 2680–2688, doi:10.3762/bjnano.8.268

• /L) is the equilibrium concentration of MB or Cu2+ in solution, qe (mg/g) is the amount adsorbed on Lys-GO, qmax (mg/g) is the maximum monolayer adsorption capacity on Lys-GO, KL (L/mol) is a coefficient related to the energy of adsorption and is expected to vary with temperature; KF (mol(1 − n)·Ln/g

Patterning of supported gold monolayers via chemical lift-off lithography

• Liane S. Slaughter,
• Kevin M. Cheung,
• Sami Kaappa,
• Huan H. Cao,
• Qing Yang,
• Thomas D. Young,
• Andrew C. Serino,
• Sami Malola,
• Jana M. Olson,
• Stephan Link,
• Hannu Häkkinen,
• Anne M. Andrews and
• Paul S. Weiss

Beilstein J. Nanotechnol. 2017, 8, 2648–2661, doi:10.3762/bjnano.8.265

• Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, and Hatos Center for Neuropharmacology, University of California, Los Angeles, Los Angeles, CA 90095, USA 10.3762/bjnano.8.265 Abstract The supported monolayer of Au that accompanies alkanethiolate molecules removed by polymer stamps

• found to be consistent with molecular dynamics simulations that predicted the removal of no more than 1.5 Au atoms per thiol, thus presenting a monolayer-like structure. Keywords: chemical patterning; hybrid material; monolayer; soft lithography; two-dimensional material; Introduction Chemical lift

• -off lithography (CLL) is a subtractive technique for patterning self-assembled alkanethiol molecules on Au surfaces via rupture of Au–Au bonds at the Au–monolayer interface [1][2]. In CLL, hydroxyl-terminated molecules (or other species with reactive termini) in preformed self-assembled monolayers

The role of ligands in coinage-metal nanoparticles for electronics

• Ioannis Kanelidis and
• Tobias Kraus

Beilstein J. Nanotechnol. 2017, 8, 2625–2639, doi:10.3762/bjnano.8.263

• ]. Elimination of a labile ligand (e.g., 3-mercaptopropanol) from the mixed ligand shell during purification of the gold nanoparticles in water created particles that were protected by only a sparse monolayer of ω-functionalized ionic ligands (25% surface coverage). The particles with the sparse layer remained

Amplified cross-linking efficiency of self-assembled monolayers through targeted dissociative electron attachment for the production of carbon nanomembranes

• Sascha Koch,
• Christopher D. Kaiser,
• Paul Penner,
• Michael Barclay,
• Lena Frommeyer,
• Daniel Emmrich,
• Patrick Stohmann,
• Tarek Abu-Husein,
• Andreas Terfort,
• D. Howard Fairbrother,
• Oddur Ingólfsson and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2017, 8, 2562–2571, doi:10.3762/bjnano.8.256

• )), implying that 2-I-BPT cross-links the fastest, followed by 2-Br-BPT, 2-Cl-BPT and finally BPT. Helium ion microscope (HIM) image of a transferred carbon nanomembrane (CNM) made using 3 min (1.8 mC/cm2) of electron irradiation (50 eV) on a 2-I-BPT self-assembled monolayer. (a) 2500 × 2500 µm HIM image of

Refractive index sensing and surface-enhanced Raman spectroscopy using silver–gold layered bimetallic plasmonic crystals

• Somi Kang,
• Sean E. Lehman,
• Matthew V. Schulmerich,
• An-Phong Le,
• Tae-woo Lee,
• Stephen K. Gray,
• Rohit Bhargava and
• Ralph G. Nuzzo

Beilstein J. Nanotechnol. 2017, 8, 2492–2503, doi:10.3762/bjnano.8.249

• ) measurements A self-assembled monolayer of benzenethiol on top of the quasi-3D PCs was prepared by immersing them in a 15 mM benzenethiol ethanolic solution for 12 h, rinsing thoroughly with ethanol, and then drying with a stream of nitrogen gas. SERS measurements were made using a SENTERRA dispersive Raman