Unveiling the nature of atomic defects in graphene on a metal surface

• Karl Rothe,
• Nicolas Néel and
• Jörg Kröger

Beilstein J. Nanotechnol. 2024, 15, 416–425, doi:10.3762/bjnano.15.37

• smallest defects appear as a depression without discernible interior structure suggesting the presence of vacancy sites in the graphene lattice. With an atomic force microscope, however, only one kind can be identified as a vacancy defect with four missing carbon atoms, while the other kind reveals an

• intact graphene sheet. Spatially resolved spectroscopy of the differential conductance and the measurement of total-force variations as a function of the lateral and vertical probe–defect distance corroborate the different character of the defects. The tendency of the vacancy defect to form a chemical

• by noble-gas ion irradiation [6][13][14][17][19][21][24], represents an opportunity for systematic defect studies. The work presented here was stimulated by the lack of experimental data on the actual geometry of atomic-scale defects in graphene. So far, scanning tunneling microscope (STM

Investigating ripple pattern formation and damage profiles in Si and Ge induced by 100 keV Ar⁺ ion beam: a comparative study

• Indra Sulania,
• Harpreet Sondhi,
• Tanuj Kumar,
• Sunil Ojha,
• G R Umapathy,
• Ambuj Mishra,
• Ambuj Tripathi,
• Richa Krishna,
• Devesh Kumar Avasthi and
• Yogendra Kumar Mishra

Beilstein J. Nanotechnol. 2024, 15, 367–375, doi:10.3762/bjnano.15.33

• photoluminescence spectroscopy. Stupp et al. [14] have explored possible applications of self-assembly of biomolecules with controlled stereochemistry in materials technology. However, the fundamental reasoning behind how this self-organization process evolves in terms of defect creation or damage still needs to be

• to analyse the crystal structure and to locate interstitial atoms within the array of target atoms. The relation between yield and defect concentration was derived by Bøgh [33]. It provides information about the depth distribution of defects in the first few microns beneath the crystalline surface

• observed for Si. This further confirms that the near surface region of Si, amorphized to form better ripple patterns in Si as compared to Ge, may be due to the overlap of the collision cascade which led to more defect formation [41]. Rutherford backscattering results The RBS technique was used to determine

Controllable physicochemical properties of WO_x thin films grown under glancing angle

• Rupam Mandal,
• Aparajita Mandal,
• Alapan Dutta,
• Rengasamy Sivakumar,
• Sanjeev Kumar Srivastava and
• Tapobrata Som

Beilstein J. Nanotechnol. 2024, 15, 350–359, doi:10.3762/bjnano.15.31

• optical bandgap and work function is thoroughly investigated by employing various spectroscopic and microscopic techniques. The systematic investigation of the work function of the films reveals a distinct trend with thickness, originating from the thickness-dependent defect concentration within the films

• . It is observed that the as-deposited NS-WOx/p-Si heterostructures are quasi-ohmic in nature. The annealed counterparts exhibit a relatively higher rectification, which points towards a possible defect-dependent Fermi level pinning at the hetero-interface. Overall, our systematic experimental

• variability in bandgap energies, we recall that the optical bandgap of this class of materials is a function of defect density and stoichiometric composition, which is mainly governed by the OV concentration within the films [39][40]. To probe any possible variation in OV concentration and stoichiometry

Determining by Raman spectroscopy the average thickness and N-layer-specific surface coverages of MoS₂ thin films with domains much smaller than the laser spot size

• Felipe Wasem Klein,
• Jean-Roch Huntzinger,
• Vincent Astié,
• Damien Voiry,
• Romain Parret,
• Houssine Makhlouf,
• Sandrine Juillaguet,
• Jean-Manuel Decams,
• Sylvie Contreras,
• Périne Landois,
• Ahmed-Azmi Zahab,
• Jean-Louis Sauvajol and
• Matthieu Paillet

Beilstein J. Nanotechnol. 2024, 15, 279–296, doi:10.3762/bjnano.15.26

• symmetry for a monolayer (A1g for bulk). These modes are located around 385 and 405 cm−1, respectively, in neutral and defect-free MoS2 monolayers [33][34]. More precisely, in MoS2 multilayers, the symmetries of these phonon modes are E′ and A′1 for an odd number of layers, and Eg and A1g for an even

• lateral size of typically 50 nm, i.e., well below the laser spot size) with possibly a distribution of thicknesses and twist angles between adjacent layers of multilayer domains and a higher number of defects (the average inter-defect distance ranges from 3 to 6 nm as estimated from the LA and A1g

Ion beam processing of DNA origami nanostructures

• Leo Sala,
• Agnes Zerolová,
• Violaine Vizcaino,
• Alain Mery,
• Alicja Domaracka,
• Hermann Rothard,
• Philippe Boduch,
• Dominik Pinkas and
• Jaroslav Kocišek

Beilstein J. Nanotechnol. 2024, 15, 207–214, doi:10.3762/bjnano.15.20

• interfaces. While we demonstrate here that the trimming of individual DNA nanostructures within the lattice is possible, the collective response of the lattice and defect formation as a response to ion impact represents an interesting direction for future studies. The processes leading to height modification

unDrift: A versatile software for fast offline SPM image drift correction

• Tobias Dickbreder,
• Franziska Sabath,
• Lukas Höltkemeier,
• Ralf Bechstein and
• Angelika Kühnle

Beilstein J. Nanotechnol. 2023, 14, 1225–1237, doi:10.3762/bjnano.14.101

• images. It is apparent that the defect positions are shifted in the second image compared to the first one. (c) Image of the cross-correlation function RXY between the images shown in (a) and (b). The center of the image and the position of the maximum are marked with red dots and connected with a red

Density functional theory study of Au-fcc/Ge and Au-hcp/Ge interfaces

• Olga Sikora,
• Małgorzata Sternik,
• Benedykt R. Jany,
• Franciszek Krok,
• Przemysław Piekarz and
• Andrzej M. Oleś

Beilstein J. Nanotechnol. 2023, 14, 1093–1105, doi:10.3762/bjnano.14.90

• variant by introducing defects into the interface layer. We investigated three supercells of variant D, in which some pairs of Au atoms in the interface layer were replaced by Ge atoms. Their optimized atomic arrangements are presented in Figure 7b–d. We can observe that while one such defect, shown in

• optimized supercell shown in Figure 9d, the interface energy is slightly higher (0.395 J/m2) than that of the defect-free junction. We also tested another type of defects (Au vacancies). To construct the supercell, we first found the position of slabs with the smallest possible Au–Ge distances (two such

• pairs per interface can be found) and removed the Au atoms from these bonds. The optimized lattice preserves the hexagonal arrangement; however, the interface energy is significantly higher than in the other considered hcp variants (0.514 J/m2). Figure 9e shows the experimental picture and the defect

Dual-heterodyne Kelvin probe force microscopy

• Benjamin Grévin,
• Fatima Husainy,
• Dmitry Aldakov and
• Cyril Aumaître

Beilstein J. Nanotechnol. 2023, 14, 1068–1084, doi:10.3762/bjnano.14.88

• depositing caesium lead halide perovskite nanosheets (NSs) on a highly oriented pyrolytic graphite (HOPG) substrate. Lead halide perovskites have emerged recently as materials with unique optical and electronic properties, such as high absorption coefficients, high defect tolerance, and charge mobility. Due

Experimental investigation of usage of POE lubricants with Al₂O₃, graphene or CNT nanoparticles in a refrigeration compressor

• Kayhan Dağıdır and
• Kemal Bilen

Beilstein J. Nanotechnol. 2023, 14, 1041–1058, doi:10.3762/bjnano.14.86

• ) can also be seen. However, D/G < 1 indicates a multilayered graphene structure, which is also seen in the micrographs shown in Figure 4a and Figure 4b. The low intensity of the D band indicates low defect density [40]. The characteristic properties of graphene are directly related to the sp2

• corresponding to the sp2-hybridised C–C system. The XPS data obtained are also consistent with previous studies [41][42]. As a result, the high purity and low defect structures of graphene nanoplatelets used in this study are understood. This supports the fact that the best improvement occurs in the graphene

Cross-sectional Kelvin probe force microscopy on III–V epitaxial multilayer stacks: challenges and perspectives

• Mattia da Lisca,
• José Alvarez,
• James P. Connolly,
• Nicolas Vaissiere,
• Karim Mekhazni,
• Jean Decobert and
• Jean-Paul Kleider

Beilstein J. Nanotechnol. 2023, 14, 725–737, doi:10.3762/bjnano.14.59

• and continuity equations numerically in two dimensions and includes flexible descriptions of bulk and surface defect distributions. KELSCAN simulates the experimental setup by sequentially moving the AFM tip across the surface of the sample, statically solving the semiconductor equations at each

• of defects extending into the volume is physically more appropriate than a simpler two-dimensional surface distribution [23]. The introduced defect volume density of states (DOS), N(E) (eV−1·cm−3), is assumed to be homogeneous throughout the thickness of the defective layer, tDL, which we took equal

• reported in Figure 6. In this specific case, the charge neutrality level of surface defects is set at mid-gap. Thus, increasing the surface defect densities will produce a pinning of the Fermi level at the neutrality level of the surface states and the energy of valence and conduction bands will appear

Transferability of interatomic potentials for silicene

• Marcin Maździarz

Beilstein J. Nanotechnol. 2023, 14, 574–585, doi:10.3762/bjnano.14.48

• -dependent interatomic potential (EDIP) fitted to various bulk phases and defect structures of Si ReaxFF [41]: the reactive force-field (ReaxFF) fitted to a training set of DFT data that pertain to Si/Ge/H bonding environments COMB [42]: the charge optimized many-body (COMB) potential fitted to a pure

Observation of multiple bulk bound states in the continuum modes in a photonic crystal cavity

• Rui Chen,
• Yi Zheng,
• Xingyu Huang,
• Qiaoling Lin,
• Chaochao Ye,
• Meng Xiong,
• Martijn Wubs,
• Yungui Ma,
• Minhao Pu and
• Sanshui Xiao

Beilstein J. Nanotechnol. 2023, 14, 544–551, doi:10.3762/bjnano.14.45

• defects are mainly located at the mode node of a specific mode, the loss caused by the defect will decrease. In contrast, disorders at an antinode will lead to obvious loss (small Qnr) and a dominant Q factor degradation. For our sample, a higher loss caused by defects occurs for the mode with shorter

Plasmonic nanotechnology for photothermal applications – an evaluation

• A. R. Indhu,
• L. Keerthana and
• Gnanaprakash Dharmalingam

Beilstein J. Nanotechnol. 2023, 14, 380–419, doi:10.3762/bjnano.14.33

• properties by phonons can thus be effectively realized by lattice tuning of the pristine materials, that is, by defect tailoring, doping, or by providing external stimuli such as pressure. While considering the actual increases in temperature of the nanoparticle possible due to plasmonic heating, the

High–low Kelvin probe force spectroscopy for measuring the interface state density

• Ryo Izumi,
• Masato Miyazaki,
• Yan Jun Li and
• Yasuhiro Sugawara

Beilstein J. Nanotechnol. 2023, 14, 175–189, doi:10.3762/bjnano.14.18

• force spectroscopy; Introduction With the recent miniaturization of semiconductor devices, understanding the physical and electrical properties of semiconductor devices, such as the dopant concentration, dopant distribution, and defect level distribution, at the nanoscale has become important. Among

• high-resolution nanoscale measurements of impurity concentration and defect level distributions at the surfaces and interfaces of various semiconductor materials and devices. (a) Schematic of the metal tip–gap–semiconductor sample. (b) Energy band diagram of the metal–gap–semiconductor sample. Emission

Gap-directed chemical lift-off lithographic nanoarchitectonics for arbitrary sub-micrometer patterning

• Chang-Ming Wang,
• Hong-Sheng Chan,
• Chia-Li Liao,
• Che-Wei Chang and
• Wei-Ssu Liao

Beilstein J. Nanotechnol. 2023, 14, 34–44, doi:10.3762/bjnano.14.4

• process provides a unique artificial defect-rich surface, which supports the creation of homogeneously distributed molecular environments for functional substrates, e.g., surface wettability control [23] and enhanced biorecognition phenomenon [24][25][26]. The versatility of CLL can also be expanded by

Induced electric conductivity in organic polymers

• Konstantin Y. Arutyunov,
• Anatoli S. Gurski,
• Vladimir V. Artemov,
• Alexander L. Vasiliev,
• Azat R. Yusupov,
• Danfis D. Karamov and
• Alexei N. Lachinov

Beilstein J. Nanotechnol. 2022, 13, 1551–1557, doi:10.3762/bjnano.13.128

• films can be obtained by centrifugation from a solution in cyclohexanone on a metal surface with a thickness from several nanometers up to micrometers. High homogeneity and defect-free surfaces on nanoscopic scales have been repeatedly confirmed by various methods, including scanning tunneling and

• strip and the whole sandwich itself. (b) Atomic force microscope scan of a PDP film 0.1 wt % on Si substrate. The plot at the bottom illustrates the roughness of the surface along the indicated line. (c) Side view of a Pb–PDP–Pb structure on glass with solitary defect (lead shortcut) obtained by

A TiO₂@MWCNTs nanocomposite photoanode for solar-driven water splitting

• Anh Quynh Huu Le,
• Ngoc Nhu Thi Nguyen,
• Hai Duy Tran,
• Van-Huy Nguyen and
• Le-Hai Tran

Beilstein J. Nanotechnol. 2022, 13, 1520–1530, doi:10.3762/bjnano.13.125

• the Raman spectrum of MWCNTs, there are two bands, that is, the D band at 1324 cm−1 and the G band at 1585 cm−1, which are ascribed to the defect structure and the ordered graphitic structure of the MWCNTs, respectively. The ratio between the D band and G band intensities (ID/IG) of the TiO2@MWCNTs

Near-infrared photoactive Ag-Zn-Ga-S-Se quantum dots for high-performance quantum dot-sensitized solar cells

• Roopakala Kottayi,
• Ilangovan Veerappan and
• Ramadasse Sittaramane

Beilstein J. Nanotechnol. 2022, 13, 1337–1344, doi:10.3762/bjnano.13.110

• . This confirms that the QDS can serve as effective sensitizers. The PL emission spectrum of AZGSSe QDs (Figure 4c) was recorded at an excitation wavelength of 295 nm. In this spectrum, a single emission peak is detected at 830 to 880 nm range with a FWHM of 20 nm. This signifies defect-free crystals [31

Recent trends in Bi-based nanomaterials: challenges, fabrication, enhancement techniques, and environmental applications

• Vishal Dutta,
• Ankush Chauhan,
• Ritesh Verma,
• C. Gopalkrishnan and
• Van-Huy Nguyen

Beilstein J. Nanotechnol. 2022, 13, 1316–1336, doi:10.3762/bjnano.13.109

• of heterojunctions, crystal plane management, and defect development, to enhance the photocatalytic efficacy of pristine Bi-based photocatalysts [1][30]. The photocatalytic processes of Bi-based photocatalytic applications have received little attention in environmental remediation and energy

• . This gap is essential for improving the material’s light-harvesting capabilities [78][79]. Consequently, in an attempt to improve the photocatalytic efficiency for water purification and other environmental applications, a variety of techniques, such as defect formation, metal/non-metal doping

• , heterostructure formation, interface modification, and Bi-content enhancement, have been employed. Defect formation Vacancies and defects affect the electrical properties of Bi-based semiconductor photocatalysts and, hence, govern the photocatalytic efficacy. Rao et al. reported an N2-assisted heat treatment

Rapid fabrication of MgO@g-C₃N₄ heterojunctions for photocatalytic nitric oxide removal

• Minh-Thuan Pham,
• Duyen P. H. Tran,
• Xuan-Thanh Bui and
• Sheng-Jie You

Beilstein J. Nanotechnol. 2022, 13, 1141–1154, doi:10.3762/bjnano.13.96

• atoms [64][65][66]. Also, Liang and co-workers reported that the recombination of the e−–h+ pairs could be inhibited by doping MgO into g-C3N4 [32]. When MgO is added, the defect concentration increases and Mg and O vacancies are generated in MgO@g-C3N4. These defects work as the electron traps, which

Biomimetic chitosan with biocomposite nanomaterials for bone tissue repair and regeneration

• Se-Kwon Kim,
• Sesha Subramanian Murugan,
• Pandurang Appana Dalavi,
• Sebanti Gupta,
• Sukumaran Anil,
• Gi Hun Seong and
• Jayachandran Venkatesan

Beilstein J. Nanotechnol. 2022, 13, 1051–1067, doi:10.3762/bjnano.13.92

• of type I collagen, osteopontin, osteonectin, and osteocalcin. Chitosan mixed with different functionalized materials such as silver, magnesium oxide, and bioactive glass has aided the treatment of infected bone defects with a biodegradable behaviour at the bone defect site [44][45]. The N-(2-hydroxy

• porous structure of the chitosan with an absorbable collagen sponge encourages osteoblast stem cells to attach to the surface to proliferate and differentiate promoting bone development. As compared to absorbable collagen sponges, the increase in bone mineral density, defect closure, and new bone

Influence of water contamination on the sputtering of silicon with low-energy argon ions investigated by molecular dynamics simulations

• Grégoire R. N. Defoort-Levkov,
• Alan Bahm and
• Patrick Philipp

Beilstein J. Nanotechnol. 2022, 13, 986–1003, doi:10.3762/bjnano.13.86

• and contaminated samples in Figure 10: For the clean sample, a smaller peak appears between the 2nd and 3rd peaks in the 2.6 to 3.2 Å region. These bonds are due to defect production in silicon after argon irradiation. For the contaminated sample, the same peak can be observed and another peak appears

Theoretical investigations of oxygen vacancy effects in nickel-doped zirconia from ab initio XANES spectroscopy at the oxygen K-edge

• Dick Hartmann Douma,
• Lodvert Tchibota Poaty,
• Alessio Lamperti,
• Stéphane Kenmoe,
• Abdulrafiu Tunde Raji,
• Alberto Debernardi and
• Bernard M’Passi-Mabiala

Beilstein J. Nanotechnol. 2022, 13, 975–985, doi:10.3762/bjnano.13.85

• and magnetic order in a typical diluted magnetic oxide. Such a finding may be crucial for spintronics-related applications. Keywords: defect; ligand field; nickel; oxidation state; oxides; spectroscopy; spintronics; vacancy; X-ray absorption; X-ray absorption near-edge structure (XANES); zirconia

• stoichiometric concentration required to ensure overall charge neutrality can modify the presence of defect states in the electron bandgap [4][26][27]. In diluted magnetic semiconductors (DMS), magnetic impurities such as the transition metals (TM) Fe or Ni are introduced to produce a magnetic ground state. The

• octahedral and trigonal bipyramidal geometries, respectively (Figure 2e,f). We present XANES spectra for defect-free zirconia, that is, without Ni dopant (x = 0 atom %), and the doped structures S0, S1, and S2 in Figure 3a. In the case of defect-free zirconia, the XANES spectrum is needed only for one oxygen

Optimizing PMMA solutions to suppress contamination in the transfer of CVD graphene for batch production

• Chun-Da Liao,
• Andrea Capasso,
• Tiago Queirós,
• Telma Domingues,
• Fatima Cerqueira,
• Nicoleta Nicoara,
• Jérôme Borme,
• Paulo Freitas and
• Pedro Alpuim

Beilstein J. Nanotechnol. 2022, 13, 796–806, doi:10.3762/bjnano.13.70

• that the PMMA mixture features good mechanical strength and cleanness (i.e., the acetone bath can thoroughly remove it). The transferred graphene samples were investigated via Raman spectroscopy to evaluate crystallinity, layer number, and structural defect level [23]. The relative intensities of the G

• (ca. 1585 cm−1) and 2D (ca. 2700 cm−1) bands are typical of monolayer graphene [23][24][25][26]. The defect density appears minimal considering the negligible D band intensity at ca. 1350 cm−1 (Figure 2c) [27]. The Raman mapping in Figure 2d–i examines the whole crystal area [28]. The map and the

Efficient liquid exfoliation of KP₁₅ nanowires aided by Hansen's empirical theory

• Zhaoxuan Huang,
• Zhikang Jiang,
• Nan Tian,
• Disheng Yao,
• Fei Long,
• Yanhan Yang and
• Danmin Liu

Beilstein J. Nanotechnol. 2022, 13, 788–795, doi:10.3762/bjnano.13.69

• Abstract The KP15 nanowires with one-dimensional properties has a defect-free surface, high anisotropy, and carrier mobility which is desirable for the development of novel nanodevices. However, the preparation of nanoscale KP15 is still inefficient. In this work, the Hansen solubility parameters of KP15

• weak interaction between these chains [3][4]. Therefore, those 1D materials have defect-free surfaces, high anisotropy, and carrier mobility. For example, TiS3 nanowires obtained by mechanical stripping have a large carrier mobility of about 10000 cm2·V−1·s−1 [5][6][7]. Fibrous phosphorus is also a new

• mobility (1000 cm2·V−1·s−1), and highly anisotropic properties [11]. The photodetectors prepared with KP15 have a fast response time and are ideal materials for photovoltaic applications [12]. Based on our previous studies, KP15 is also a one-dimensional material with a defect-free surface [13][14]. This