Kelvin probe force microscopy for local characterisation of active nanoelectronic devices

• Tino Wagner,
• Hannes Beyer,
• Patrick Reissner,
• Philipp Mensch,
• Heike Riel,
• Bernd Gotsmann and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2015, 6, 2193–2206, doi:10.3762/bjnano.6.225

• established technique that allows for the mapping of local electrostatic potentials with an atomic force microscope (AFM) [1][2][3]. In contrast to electrostatic force microscopy (EFM), which measures merely the effect of electrostatic forces on the oscillation of the tip, a feedback loop nullifies the

• the main reason for the notoriously low lateral resolution and poor potential accuracy in this mode. When comparing AM and FM modes, one should note that in lift-mode AM-KFM the cantilever is not oscillating anymore when the electrostatic forces are nullified, whereas the mechanical oscillation

Electrospray deposition of organic molecules on bulk insulator surfaces

• Antoine Hinaut,
• Rémy Pawlak,
• Ernst Meyer and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2015, 6, 1927–1934, doi:10.3762/bjnano.6.195

• distributed all over the surface and appear up to 3 nm high. However, no clear organization of the molecules was observed. Large electrostatic forces have been observed and measured via frequency shift versus voltage curves df(V) [40] after the deposition process. These could not be compensated during

• measurements by applying a bias voltage of up to ±10 V, which is the limit of the AFM system. These large electrostatic forces induced difficult scan conditions and we were not able to study the organization of the molecules in more detail. Indeed, surfaces charges of bulk insulator samples have already been

• studied in detail [41][42]. Due to cleavage many charges can be created resulting in large electrostatic forces. Sample preparation with soft annealing is well-established and leads to only a few remaining isolated charges [42]. Since the sample was prepared with such procedure before UHV-ESI deposition

PLGA nanoparticles as a platform for vitamin D-based cancer therapy

• Maria J. Ramalho,
• Joana A. Loureiro,
• Bárbara Gomes,
• Manuela F. Frasco,
• Manuel A. N. Coelho and
• M. Carmo Pereira

Beilstein J. Nanotechnol. 2015, 6, 1306–1318, doi:10.3762/bjnano.6.135

• electrostatic forces due to the PLGA carboxylate groups at the NP surface, and the surfactant behavior that also plays a crucial role in maintaining nanosuspension stabilization. During particle formation, the Pluronic®F127 is adsorbed onto the NP surface, providing steric and thermodynamic stabilization

Morphological and structural characterization of single-crystal ZnO nanorod arrays on flexible and non-flexible substrates

• Omar F. Farhat,
• Mohd M. Halim,
• Mat J. Abdullah,
• Mohammed K. M. Ali and
• Nageh K. Allam

Beilstein J. Nanotechnol. 2015, 6, 720–725, doi:10.3762/bjnano.6.73

• active, while the E and TO are forbidden. Due to the long-range electrostatic forces, the phonons with A1 and E symmetry are polar and hence exhibit different frequencies for the TO and LO phonons. Every mode corresponds to a band in the Raman spectrum, with the A1 phonon vibration polarized parallel to

Boosting the local anodic oxidation of silicon through carbon nanofiber atomic force microscopy probes

• Gemma Rius,
• Matteo Lorenzoni,
• Soichiro Matsui,
• Masaki Tanemura and
• Francesc Perez-Murano

Beilstein J. Nanotechnol. 2015, 6, 215–222, doi:10.3762/bjnano.6.20

• –sample direct mechanical contact or long range interactions, such as based on van der Waals or electrostatic forces. Because of this, AFM-based SPL can be achieved through oxidation, indentation, as well as various other implementations such as dip-pen nanolithography [5]. Early works on AFM-based SPL

Kelvin probe force microscopy in liquid using electrochemical force microscopy

• Liam Collins,
• Stephen Jesse,
• Jason I. Kilpatrick,
• Alexander Tselev,
• M. Baris Okatan,
• Sergei V. Kalinin and
• Brian J. Rodriguez

Beilstein J. Nanotechnol. 2015, 6, 201–214, doi:10.3762/bjnano.6.19

• a role in shifting the measured CPD of the Au surface outside of the bias range studied. In order to investigate the possibility that the CPD of Au was shifted in liquid, and to further investigate the dependence of electrostatic forces at larger biases, Aω and A2ω were probed under increasing bias

Intake of silica nanoparticles by giant lipid vesicles: influence of particle size and thermodynamic membrane state

• Florian G. Strobl,
• Florian Seitz,
• Christoph Westerhausen,
• Armin Reller,
• Adriano A. Torrano,
• Christoph Bräuchle,
• Achim Wixforth and
• Matthias F. Schneider

Beilstein J. Nanotechnol. 2014, 5, 2468–2478, doi:10.3762/bjnano.5.256

• realistic scenario are significantly stronger than those that are necessary for an uptake in our model system (see Figure 4). In the case of anionic or neutral particles, electrostatic forces will, of course, not be sufficient for an uptake. However, binding of proteins can provide strong adhesion

Aquatic versus terrestrial attachment: Water makes a difference

• Petra Ditsche and
• Adam P. Summers

Beilstein J. Nanotechnol. 2014, 5, 2424–2439, doi:10.3762/bjnano.5.252

• substantial variability and we cannot calculate a reasonable attachment force for the whole animal from measurements of a single seta, tube foot or sucker. Adhesion A variety of different mechanisms contributes to adhesion: (i) mechanical interlocking on a very small scale, (ii) electrostatic forces, (iii

Liquid-phase exfoliated graphene: functionalization, characterization, and applications

• Mildred Quintana,
• Jesús Iván Tapia and
• Maurizio Prato

Beilstein J. Nanotechnol. 2014, 5, 2328–2338, doi:10.3762/bjnano.5.242

• the interplay of electrostatic forces and π-electron clouds on graphene. The proximity of the Ru4POM to the graphene surface in the arylation reaction leads to a tight immobilization. Imaging on graphene Finally, the optical properties of graphene for the high contrast imaging of the two previously

Sequence-dependent electrical response of ssDNA-decorated carbon nanotube, field-effect transistors to dopamine

• Hari Krishna Salila Vijayalal Mohan,
• Jianing An and
• Lianxi Zheng

Beilstein J. Nanotechnol. 2014, 5, 2113–2121, doi:10.3762/bjnano.5.220

• electrostatic forces; thereby the neutral mixture fails to produce any effect on the SWCNT [23]. Thus, detecting DA in the presence of UA is a challenge because of the electrical neutrality of the mixture and the hydrophobic nature of the SWCNT. This discourages the attachment of polar molecules onto the

• could be because of strong interactions such as hydrogen bonding, or mutual association of the hydrophobic regions between DA and ssDNA, or weak electrostatic attractions. According to earlier reports [33], the electrostatic forces are the dominant forces of interaction between ssDNA and DA. Since DA is

Controlling the dispersion of supported polyoxometalate heterogeneous catalysts: impact of hybridization and the role of hydrophilicity–hydrophobicity balance and supramolecularity

• Gijo Raj,
• Colas Swalus,
• Eglantine Arendt,
• Pierre Eloy,
• Michel Devillers and
• Eric M. Gaigneaux

Beilstein J. Nanotechnol. 2014, 5, 1749–1759, doi:10.3762/bjnano.5.185

• POM, respectively, the total height of the hybrid assembly nearly doubles. This is also an indication that the organic–inorganic hybridization is largely dependent on the strength of electrostatic forces. In order to further understand the hybrid materials, we were motivated to identify the POM anions

Hydrophobic interaction governs unspecific adhesion of staphylococci: a single cell force spectroscopy study

• Nicolas Thewes,
• Peter Loskill,
• Philipp Jung,
• Henrik Peisker,
• Markus Bischoff,
• Mathias Herrmann and
• Karin Jacobs

Beilstein J. Nanotechnol. 2014, 5, 1501–1512, doi:10.3762/bjnano.5.163

• , yet it is unclear up to now which forces are governing this process. Alongside long-ranged van der Waals and electrostatic forces, short-ranged hydrophobic interaction plays an important role. To characterize the forces involved during approach and retraction of an individual bacterium to and from a

• bacterium, the surrounding medium, the surface chemistry, and the material composition reflecting the influence of the main interacting forces [12][13]: van der Waals forces, hydrophobic interaction and electrostatic forces. In addition, specific interactions amplify bacterial adhesion whenever

• ), which explains the present results. What is the difference of bacterial adhesion to hydrophilic or hydrophobic surfaces? Adhesion is the sum of all forces between the interacting partners. In our case, van der Waals and electrostatic forces as well as forces due to the hydrophobic interaction are

The study of surface wetting, nanobubbles and boundary slip with an applied voltage: A review

• Yunlu Pan,
• Bharat Bhushan and
• Xuezeng Zhao

Beilstein J. Nanotechnol. 2014, 5, 1042–1065, doi:10.3762/bjnano.5.117

Uncertainties in forces extracted from non-contact atomic force microscopy measurements by fitting of long-range background forces

• Adam Sweetman and
• Andrew Stannard

Beilstein J. Nanotechnol. 2014, 5, 386–393, doi:10.3762/bjnano.5.45

• electrostatic forces. Typically, the contribution from these forces must be removed before the results of the experiment can be successfully interpreted, often by comparison to density functional theory calculations. In this paper we compare the ‘on-minus-off’ method for extracting site-specific forces to a

Effect of contaminations and surface preparation on the work function of single layer MoS₂

• Oliver Ochedowski,
• Kolyo Marinov,
• Nils Scheuschner,
• Artur Poloczek,
• Benedict Kleine Bussmann,
• Janina Maultzsch and
• Marika Schleberger

Beilstein J. Nanotechnol. 2014, 5, 291–297, doi:10.3762/bjnano.5.32

• resonance frequency of f = 300 kHz (Vistaprobe T300) were utilized. During KPFM measurements an AC voltage is applied to the tip (UAC = 1 V and fAC = 1 kHz) and the built in lock-in amplifier of the PLL Pro 2 is used to apply a DC voltage which minimizes the resulting electrostatic forces between tip and

Influence of the adsorption geometry of PTCDA on Ag(111) on the tip–molecule forces in non-contact atomic force microscopy

• Gernot Langewisch,
• Jens Falter,
• André Schirmeisen and
• Harald Fuchs

Beilstein J. Nanotechnol. 2014, 5, 98–104, doi:10.3762/bjnano.5.9

• electrostatic forces or Pauli repulsion is reached. These forces most likely lead to the barbell-like structure as shown in Figure 3b at z = 0.65 nm with higher attractive forces at the end groups. While the physical origin of this contrast is not clear, a likely explanation for the structure that illustrated

Noise performance of frequency modulation Kelvin force microscopy

• Heinrich Diesinger,
• Dominique Deresmes and
• Thierry Mélin

Beilstein J. Nanotechnol. 2014, 5, 1–18, doi:10.3762/bjnano.5.1

• electrostatic forces in amplitude modulation Kelvin force microscopy (AM-KFM) [1] or the measurement of the electrostatic force gradient in FM-KFM [2], in analogy with the FM mode used in noncontact atomic force microscopy (nc-AFM) [3]. The FM-KFM mode is often favored either because when a higher derivative of

Routes to rupture and folding of graphene on rough 6H-SiC(0001) and their identification

• M. Temmen,
• O. Ochedowski,
• B. Kleine Bussmann,
• M. Schleberger,
• M. Reichling and
• T. R. J. Bollmann

Beilstein J. Nanotechnol. 2013, 4, 625–631, doi:10.3762/bjnano.4.69

• ] imaging is performed simultaneously by applying an AC voltage of 1 V amplitude at a frequency of 1.2 kHz added to the DC bias regulated to minimize electrostatic forces. To remove volatile surface contaminants that can significantly influence LCPD measurements [25], the sample is heated in UHV to 500 K

Kelvin probe force microscopy of nanocrystalline TiO₂ photoelectrodes

• Alex Henning,
• Gino Günzburger,
• Res Jöhr,
• Yossi Rosenwaks,
• Biljana Bozic-Weber,
• Catherine E. Housecroft,
• Edwin C. Constable,
• Ernst Meyer and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2013, 4, 418–428, doi:10.3762/bjnano.4.49

• -potential detection method that determines the contact potential difference (CPD) during scanning by compensating the electrostatic forces between a microscopic tip and the sample [34]. Figure 2a illustrates a schematic band diagram for a KPFM tip in close proximity to a semiconductor sample surface with

Diamond nanophotonics

• Katja Beha,
• Helmut Fedder,
• Marco Wolfer,
• Merle C. Becker,
• Petr Siyushev,
• Mohammad Jamali,
• Anton Batalov,
• Christopher Hinz,
• Jakob Hees,
• Lutz Kirste,
• Harald Obloh,
• Etienne Gheeraert,
• Boris Naydenov,
• Ingmar Jakobi,
• Florian Dolde,
• Sébastien Pezzagna,
• Daniel Twittchen,
• Matthew Markham,
• Daniel Dregely,
• Harald Giessen,
• Jan Meijer,
• Fedor Jelezko,
• Christoph E. Nebel,
• Rudolf Bratschitsch,
• Alfred Leitenstorfer and
• Jörg Wrachtrup

Beilstein J. Nanotechnol. 2012, 3, 895–908, doi:10.3762/bjnano.3.100

• nm, which is well suited for high-energy implantation with high spatial resolution. The channels have a rhombic cross section that reflects the crystal structure of the mica. The mica mask is then placed on the surface of a diamond. Electrostatic forces ensure good sticking of the mica sheet on the

Simultaneous current, force and dissipation measurements on the Si(111) 7×7 surface with an optimized qPlus AFM/STM technique

• Zsolt Majzik,
• Martin Setvín,
• Andreas Bettac,
• Albrecht Feltz,
• Vladimír Cháb and
• Pavel Jelínek

Beilstein J. Nanotechnol. 2012, 3, 249–259, doi:10.3762/bjnano.3.28

• STM/AFM measurements on the Si(111) 7×7 surface using our modified sensor. The measurements were performed in the constant frequency shift mode at room temperature. To compensate for long-range electrostatic forces, the bias voltage was adjusted to the minimum of the Kelvin parabola (generally about

Modeling noncontact atomic force microscopy resolution on corrugated surfaces

• Kristen M. Burson,
• Mahito Yamamoto and
• William G. Cullen

Beilstein J. Nanotechnol. 2012, 3, 230–237, doi:10.3762/bjnano.3.26

• is minimized, especially when seeking accurate topography of corrugated surfaces. The model used does not account for local bonding, electrostatic forces, or atomistic interactions beyond the inclusion of a pairwise vdW interaction, all of which affect the AFM resolution; nonetheless, even if these

• rough surfaces, the model itself oversimplifies the multifaceted complexities of experimental AFM setups. More complex models, which include short-range bonding and electrostatic forces, more realistic tip geometries, and calculations for closer proximities between tip and sample, are needed for a more

An NC-AFM and KPFM study of the adsorption of a triphenylene derivative on KBr(001)

• Antoine Hinaut,
• Adeline Pujol,
• Florian Chaumeton,
• David Martrou,
• André Gourdon and
• Sébastien Gauthier

Beilstein J. Nanotechnol. 2012, 3, 221–229, doi:10.3762/bjnano.3.25

• still very scarce [6][8]. Coupling these two techniques is not only interesting for the characterization of the electrical properties of the adsorbates, but also for the extraction of topographic images that are free from distortion induced by electrostatic forces [27]. In the following, we present the

• normalized frequency shifts [33] γ = kA3/2Δf/f0 = 0.25 fN·m1/2 at most (k ~ 40 N·m−1). Under these conditions the interaction of the tip with the surface is quite small and it is expected that only van der Waals and electrostatic forces contribute to the image. Note that at the Kelvin voltage, provided that

Noncontact atomic force microscopy study of the spinel MgAl₂O₄(111) surface

• Morten K. Rasmussen,
• Kristoffer Meinander,
• Flemming Besenbacher and
• Jeppe V. Lauritsen

Beilstein J. Nanotechnol. 2012, 3, 192–197, doi:10.3762/bjnano.3.21

• scanning the surface. The surface potential, measured after annealing the crystal, was generally quite high, often in the range 4–8 V. Therefore, the voltage applied between the surface and the tip, Ubias, was monitored and adjusted regularly to minimize the electrostatic forces arising from the contact

Molecular-resolution imaging of pentacene on KCl(001)

• Julia L. Neff,
• Jan Götzen,
• Enhui Li,
• Michael Marz and
• Regina Hoffmann-Vogel

Beilstein J. Nanotechnol. 2012, 3, 186–191, doi:10.3762/bjnano.3.20

• -range electrostatic forces, the tip–sample work-function difference was compensated by application of the appropriate bias voltage to the tip. Results and Discussion Figure 1a shows the KCl(001) surface with submonolayer coverage of pentacene molecules forming an extended island over several microns