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

• charge regions and, thus, the presence of several junctions along the stack. Furthermore, a contrast enhancement in the surface potential image was observed when KPFM was performed under illumination, which is analysed in terms of the reduction of surface band bending induced by surface defects by

• interpretation of the KPFM data, specifically to investigate the effect of space charge regions, surface defects, and illumination on VCPD [13]. Experimental Sample preparation The structure of the studied sample is summarized in Table 1. This multilayer stack structure was epitaxially grown using a MOVPE

• section was used. KPFM is a surface technique; therefore, KPFM measurements are strongly influenced by the presence of surface defects. In order to provide a quantitative analysis of the experimental results, KELSCAN allows for the introduction of defects in a surface layer of arbitrary depth. The model

Bismuth-based nanostructured photocatalysts for the remediation of antibiotics and organic dyes

• Akeem Adeyemi Oladipo and
• Faisal Suleiman Mustafa

Beilstein J. Nanotechnol. 2023, 14, 291–321, doi:10.3762/bjnano.14.26

• /and surface defects are created without destroying the crystal structure (though it might be distorted), effectively separating photogenerated carriers. Doping with metallic (Mg, Ag, Ni, Fe, Li, Co, and Ni) and non-metallic ions (F, C, N, and O), can introduce an intraband close to the conduction band

Structural, optical, and bioimaging characterization of carbon quantum dots solvothermally synthesized from o-phenylenediamine

• Zoran M. Marković,
• Milica D. Budimir,
• Martin Danko,
• Dušan D. Milivojević,
• Pavel Kubat,
• Danica Z. Zmejkoski,
• Vladimir B. Pavlović,
• Marija M. Mojsin,
• Milena J. Stevanović and
• Biljana M. Todorović Marković

Beilstein J. Nanotechnol. 2023, 14, 165–174, doi:10.3762/bjnano.14.17

• from this, surface defects can cause a redshift of the PL emission [35]. Based on the recorded PL spectra, we can conclude that the PL of these dots is dominantly governed by the core states in the conjugated π domains and the quantum confinement effect. Similar to other semiconducting quantum dots

Antimicrobial and mechanical properties of functionalized textile by nanoarchitectured photoinduced Ag@polymer coating

• Jessica Plé,
• Marine Dabert,
• Helene Lecoq,
• Sophie Hellé,
• Lydie Ploux and
• Lavinia Balan

Beilstein J. Nanotechnol. 2023, 14, 95–109, doi:10.3762/bjnano.14.11

• ] synthesized AgNPs on cotton fabrics using laser ablation, while Ahmad et al. [31] deposited AgNPs by the dip and dry method based on surface reduction reactions. However, the difference in expansion coefficients of the given metal layer and substrate can lead to surface defects under strain (cracks, loss of

Recent advances in green carbon dots (2015–2022): synthesis, metal ion sensing, and biological applications

• Aisha Kanwal,
• Naheed Bibi,
• Sajjad Hyder,
• Arif Muhammad,
• Hao Ren,
• Jiangtao Liu and
• Zhongli Lei

Beilstein J. Nanotechnol. 2022, 13, 1068–1107, doi:10.3762/bjnano.13.93

• . Surface passivation with different functional groups generates surface defects, which produces fluorescence and also generates new active sites for modification for specific applications. CDs can be chemically modified by many heteroatoms, including N, P, and S, and many other chemicals that increase

• high QY because nitrogen atom doping helps to stabilize the surface defects of CDs and enhances fluorescence emission. Moreover, owing to its five valence electrons and an atomic size that is similar to carbon, nitrogen is a common dopant and the most frequently employed method of enhancing PL

• demonstrated that the level of surface oxidation in CDs is what causes their luminescence. The amount of oxygen on the surface of CDs directly influences its redshifted emission. The number of surface defects increases with the surface oxidation level. The surface defects trap excitons, and the radiation from

Hierarchical Bi₂WO₆/TiO₂-nanotube composites derived from natural cellulose for visible-light photocatalytic treatment of pollutants

• Zehao Lin,
• Zhan Yang and
• Jianguo Huang

Beilstein J. Nanotechnol. 2022, 13, 745–762, doi:10.3762/bjnano.13.66

• three weak peaks at 448, 479, and 490 nm, which are indexed to the recombination of photoinduced electron−hole pairs, freely excited electrons, surface defects, and oxygen vacancies on the band edges, respectively [36][61]. It is apparent that the PL intensities of the Bi2WO6/TiO2-NT nanocomposites at

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

• also benefits the SERS enhancement. Doping zinc oxide–Ag nanoparticles with magnesium also introduces defect sites (surface defects and oxygen vacancies), which form new energy levels below the conduction band of zinc oxide, facilitating the charge transfer mechanism. In this case, besides the charge

Irradiation-driven molecular dynamics simulation of the FEBID process for Pt(PF₃)₄

• Alexey Prosvetov,
• Alexey V. Verkhovtsev,
• Gennady Sushko and
• Andrey V. Solov’yov

Beilstein J. Nanotechnol. 2021, 12, 1151–1172, doi:10.3762/bjnano.12.86

• with the results of [31]. The van der Waals forces between the atoms of the substrate and the adsorbed molecules are described by means of the Lennard-Jones potential: where and . Note that partial hydroxylation, surface defects, and broken O–H bonds may lead to a stronger interaction between Pt and

Interface interaction of transition metal phthalocyanines with strontium titanate (100)

• Reimer Karstens,
• Thomas Chassé and
• Heiko Peisert

Beilstein J. Nanotechnol. 2021, 12, 485–496, doi:10.3762/bjnano.12.39

• part of the TMPcFx molecules in the first monolayer might be related to local interactions with Ti and/or Sr atoms. Also, interactions between the macrocycle of the TMPc and the rutile TiO2 surfaces seem to depend critically on the number of surface defects [50]. Thus, the absence of interface

Extended iron phthalocyanine islands self-assembled on a Ge(001):H surface

• Rafal Zuzak,
• Marek Szymonski and
• Szymon Godlewski

Beilstein J. Nanotechnol. 2021, 12, 232–241, doi:10.3762/bjnano.12.19

• analysis of single FePc molecules trapped at surface defects indicates that the molecules stay intact upon adsorption and can be manipulated away from surface defects onto a perfectly hydrogenated surface. This allows for their isolation from the germanium surface. Keywords: hydrogenated semiconductor

• nanoislands. Our STM data indicate that FePc molecules stay intact upon adsorption. While single molecules are trapped at surface defects and could be manipulated with the STM tip away from the defects onto the perfectly hydrogenated Ge(001):H surface, the major fraction of the molecules could be found within

• atomic-scale defects and our previous experiments with other organic molecules [35], we may expect that single FePc molecules on the surface are trapped at surface defects, although the formation of molecular islands hints at a sufficient mobility of the molecules on the Ge(001):H surface. In a

ZnO and MXenes as electrode materials for supercapacitor devices

• Ameen Uddin Ammar,
• Ipek Deniz Yildirim,
• Feray Bakan and
• Emre Erdem

Beilstein J. Nanotechnol. 2021, 12, 49–57, doi:10.3762/bjnano.12.4

• ≈ 2.004, which is very close to the value of g of free electrons. The surface defects accumulated in the shell of the nanocrystal give a value of g similar to that of free electrons due to their delocalization [2][3][5]. This information can only be obtained via EPR spectroscopy. The intensity of the

• information has been obtained from the electrical analysis of bulk and nanoscale ZnO as electrode material in supercapacitor devices [7][10][11]. Bulk ZnO exhibits typical electric double-layer capacitor (EDLC) character. Using nanoscale ZnO, however, due to the effect of the surface defects, the device shows

• defects and the performance as electrode in supercapacitor devices. (a) X-band EPR spectra indicating two distinct signals with g-factors of 1.96 and 2.00 arising from the core and from surface defects, respectively [1][2][3][4][5][6]. These are paramagnetic defects, which are mainly singly or doubly

Nanocasting synthesis of BiFeO₃ nanoparticles with enhanced visible-light photocatalytic activity

• Thomas Cadenbach,
• Maria J. Benitez,
• A. Lucia Morales,
• Cesar Costa Vera,
• Luis Lascano,
• Francisco Quiroz,
• Alexis Debut and
• Karla Vizuete

Beilstein J. Nanotechnol. 2020, 11, 1822–1833, doi:10.3762/bjnano.11.164

• catalytic performance in terms of overall degradation efficiency of the 5.5 nm particles is significantly superior compared to those of similarly sized particles reported. It also much improved when compared with samples free of surface defects synthesized by a previously reported co-precipitation method

• very narrow particle size distribution. The results also suggest that the nanoparticles are characterized by a low concentration of surface defects and a low level of local strain, which is ideal for surface-based applications such as photocatalysis. This is confirmed by the reaction kinetics of the

• sized particles. This behavior can be attributed to a low concentration of surface defects and low local strain. The photocatalyst proved to be stable under visible-light irradiation as it could be reapplied successfully in five successive photocatalytic degradation experiments without loss of

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

• the optical excitation can occur. The different FL lines can be ascribed to different environments of the adsorption sites, namely molecules adsorbed at surface defects, in large ordered domains, and located in the second layer. Keywords: decoupling; fluorescence; hexagonal boron nitride; 3,4,9,10

• spectrum). An enhancement of radiative interband transitions has been reported for Cu nanoparticles [40]. We thus speculate that surface defects (protrusions) play a role here. This is in agreement with our observation that the intensity of this “defect luminescence” in region I depends on the exact

• additional enhancement [46]. According to the electromagnetic mechanism, on a rough surface, surface plasmon polaritons (SPPs) can also be excited by the incident light. The surface plasmons are located in the vicinity of surface defects, such as protrusions. The field enhancement at these defects leads to

Atomic defect classification of the H–Si(100) surface through multi-mode scanning probe microscopy

• Jeremiah Croshaw,
• Thomas Dienel,
• Taleana Huff and
• Robert Wolkow

Beilstein J. Nanotechnol. 2020, 11, 1346–1360, doi:10.3762/bjnano.11.119

• platform for the development of atom scale devices, with recent work showing their creation through precise desorption or placement of surface hydrogen atoms. While samples with relatively large areas of the H–Si surface are routinely created using an in situ methodology, surface defects are inevitably

• . With this, we take the first steps toward enabling the creation of superior H–Si surfaces through an improved understanding of surface defects, ultimately leading to more consistent and reliable fabrication of atom scale devices. Keywords: atomic force microscopy; hydrogen-terminated silicon; scanning

• dimers are formed, which run parallel along the surface. The study of Si(100) surface defects was one of the first applications of scanning probe microscopy [14]. The three observed species were identified as a missing silicon dimer, a pair of missing silicon dimers, and a missing pair of Si atoms on the

Gas sorption porosimetry for the evaluation of hard carbons as anodes for Li- and Na-ion batteries

• Yuko Matsukawa,
• Fabian Linsenmann,
• Maximilian A. Plass,
• George Hasegawa,
• Katsuro Hayashi and
• Tim-Patrick Fellinger

Beilstein J. Nanotechnol. 2020, 11, 1217–1229, doi:10.3762/bjnano.11.106

• electrolyte. It was further shown that additional irreversible capacity can arise from alkali metal ions reacting with surface defects or reactive surface groups and small molecules other than the electrolyte adsorbed to the walls of nanometric pores that were not removed during the cell production [17

Adsorption behavior of tin phthalocyanine onto the (110) face of rutile TiO₂

• Lukasz Bodek,
• Mads Engelund,
• Aleksandra Cebrat and
• Bartosz Such

Beilstein J. Nanotechnol. 2020, 11, 821–828, doi:10.3762/bjnano.11.67

• increasing coverage, a few stable single molecules can be found, which are most likely stabilized by surface defects, as well as stable molecular assemblies in limited areas close to terrace edges, where movement is hampered by steric interactions (Figure S2, Supporting Information File 1). The

• -range dispersive forces. The fact that the Sn-down geometry is preferred could be rationalized by assuming that the Sn atom locates between surface hydroxy groups, allowing for attractive interactions between positive surface defects and negatively charged pyrrole-like subunits. Such a geometry can

• surface in a flat-lying position, but their mobility renders imaging impossible. With increasing coverage, increasingly more molecules appear to be stable due to either the influence of surface defects or steric interactions. However, SnPcs do not form a well-defined, regular structure, which suggests

Interfacial charge transfer processes in 2D and 3D semiconducting hybrid perovskites: azobenzene as photoswitchable ligand

• Nicole Fillafer,
• Tobias Seewald,
• Lukas Schmidt-Mende and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2020, 11, 466–479, doi:10.3762/bjnano.11.38

• and AzoOC12), which can be seen in Figure 6B. As many other charge-carrier dynamics beside the radiative recombination, such as photorecycling and surface defects, affect the PL no (bi)exponential fit could be found [53][54]. Thus, the recorded measurements are discussed qualitatively. A small spacing

Atomic-resolution imaging of rutile TiO₂(110)-(1 × 2) reconstructed surface by non-contact atomic force microscopy

• Daiki Katsube,
• Shoki Ojima,
• Eiichi Inami and
• Masayuki Abe

Beilstein J. Nanotechnol. 2020, 11, 443–449, doi:10.3762/bjnano.11.35

• information on the line defect. The line defects could be due to be sub-surface defects because of the geometry of the reflected top surface obtained in NC-AFM imaging using the interaction between the tip and the sample surface as a feedback signal. To identify the line defects, it is necessary to combine

Synthesis and enhanced photocatalytic performance of 0D/2D CuO/tourmaline composite photocatalysts

• Changqiang Yu,
• Min Wen,
• Zhen Tong,
• Shuhua Li,
• Yanhong Yin,
• Xianbin Liu,
• Yesheng Li,
• Tongxiang Liang,
• Ziping Wu and
• Dionysios D. Dionysiou

Beilstein J. Nanotechnol. 2020, 11, 407–416, doi:10.3762/bjnano.11.31

• -type CuO semiconductor is ≈1.2 eV [6]. The application of CuO covers the fields of photocatalytic degradation of organic contaminants [7], photocatalytic reduction of CO2 [8][9], photocatalytic splitting of water [10], etc. Nanoscale CuO has been widely studied owing to its increased surface defects

Formation of nanoripples on ZnO flat substrates and nanorods by gas cluster ion bombardment

• Xiaomei Zeng,
• Vasiliy Pelenovich,
• Bin Xing,
• Rakhim Rakhimov,
• Wenbin Zuo,
• Alexander Tolstogouzov,
• Chuansheng Liu,
• Dejun Fu and
• Xiangheng Xiao

Beilstein J. Nanotechnol. 2020, 11, 383–390, doi:10.3762/bjnano.11.29

• local defects of the flat surface (initially existing or created by the irradiation) initiate the formation of ripple trains [8][25]. If a nanorod is exposed to the irradiation, then the edges between the side facets and the ends can play the role of such surface defects. Our experiment does confirm the

• role of boundary surface defects in ripple formation. In Figure 6c one can see the formation of two to three ordered nanoripples oriented parallel to the end edge. A similar mechanism influences the ripple formation at higher energy and fluences, i.e., when the ripple wavelength becomes larger (Figure

Polyvinylpyrrolidone as additive for perovskite solar cells with water and isopropanol as solvents

• Chen Du,
• Shuo Wang,
• Xu Miao,
• Wenhai Sun,
• Yu Zhu,
• Chengyan Wang and
• Ruixin Ma

Beilstein J. Nanotechnol. 2019, 10, 2374–2382, doi:10.3762/bjnano.10.228

• slight decline in the FWHM of the final product, which indicates a reduction in surface defects. The J–V curves of the films with optimal amount of PVP additive and without PVP additive are shown in Figure 8a. The preparation of a perovskite solar cell using a PVP-containing aqueous lead nitrate

• PCE after as little as 400 h. The higher stability in ambient air is attributed to the lower number of surface defects [38]. Conclusion The photovoltaic performance of PSCs with an aqueous lead nitrate solution as the precursor was enhanced through the addition of PVP. The PVP additive influenced the

The role of Ag⁺, Ca²⁺, Pb²⁺ and Al³⁺ adions in the SERS turn-on effect of anionic analytes

• Stefania D. Iancu,
• Andrei Stefancu,
• Vlad Moisoiu,
• Loredana F. Leopold and
• Nicolae Leopold

Beilstein J. Nanotechnol. 2019, 10, 2338–2345, doi:10.3762/bjnano.10.224

• surface of the cit-AgNPs such as surface defects and kinks [36][37] and will increase the number of available positively charged adsorption sites for anionic analytes. As highlighted by Attard, the polarizability of the adion will influence greatly its surface activity [35]. This explains why cations with

Nitrogen-vacancy centers in diamond for nanoscale magnetic resonance imaging applications

• Alberto Boretti,
• Lorenzo Rosa,
• Jonathan Blackledge and
• Stefania Castelletto

Beilstein J. Nanotechnol. 2019, 10, 2128–2151, doi:10.3762/bjnano.10.207

• the oxygen molecule absorption edge and can selectively remove the ND surface defects. A decrease in the FWHM of the ODMR spectra close to 15% and an increase in the T2 time of almost 25% are observed, with a maximum T2 of 2 µs. This technique is quite simple and produces better magnetic imaging

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

• . The steep absorption edge near 380 nm originates from the intrinsic absorption of TiO2, i.e., the absorption results from the transition of electrons from the valence band to the conduction band. The undoped 2-S0 sample exhibits a "tail-like" absorption between 400 and 500 nm, possibly due to surface

• defects such as oxygen vacancies. The absorption spectrum of the 2-S0.5 sample shows a peak at 460 nm. The visible-light absorption of the samples with RS/Ti ≥ 1, where S2− replaces O2− and S6+ replaces Ti4+, is caused by cooperative effects of the oxygen vacancies and the substituted S elements. The

Warped graphitic layers generated by oxidation of fullerene extraction residue and its oxygen reduction catalytic activity

• Machiko Takigami,
• Rieko Kobayashi,
• Takafumi Ishii,
• Yasuo Imashiro and
• Jun-ichi Ozaki

Beilstein J. Nanotechnol. 2019, 10, 1391–1400, doi:10.3762/bjnano.10.137

• . Controlling carbonization by metal catalysts such as iron or cobalt produces nanoshell-containing carbon (NSCC) with ORR activity [30][31][32][33][34][35]. This activity is thought to originate from surface defects formed on the nanoshell carbons, including edges and warped graphitic layers (WGLs) [31][36