High-resolution noncontact AFM and Kelvin probe force microscopy investigations of self-assembled photovoltaic donor–acceptor dyads

• Benjamin Grévin,
• Pierre-Olivier Schwartz,
• Laure Biniek,
• Martin Brinkmann,
• Nicolas Leclerc,
• Elena Zaborova and
• Stéphane Méry

Beilstein J. Nanotechnol. 2016, 7, 799–808, doi:10.3762/bjnano.7.71

• dyads are used as model nanostructured heterojunctions for local investigations by noncontact atomic force microscopy (nc-AFM) and Kelvin probe force microscopy (KPFM). With the aim to probe the photo-induced charge carrier generation, thin films deposited on transparent indium tin oxide substrates are

• elementary building block level. Keywords: donor–acceptor co-oligomers; donor–acceptor lamellae; donor–acceptor-ordered bulk heterojunction; Kelvin probe force microscopy (KPFM); noncontact atomic force microscopy (nc-AFM); organic photovoltaics; surface photo-voltage (SPV); Introduction Nowadays, with

• lamellae but with a majority of edge-on co-oligomers. In this work, two samples with n = 1 (AD1) and n = 3 (AD3) were investigated by nc-AFM and KPFM in the form of thin films (a few tens of nm thick) deposited on functionalized indium tin oxide substrates. Most of the surface photo-voltage investigations

Rigid multipodal platforms for metal surfaces

• Michal Valášek,
• Marcin Lindner and
• Marcel Mayor

Beilstein J. Nanotechnol. 2016, 7, 374–405, doi:10.3762/bjnano.7.34

• adamantane-based tripodal molecules have been reported by Yamakoshi and co-workers [83][90]. They designed and examined azobenzene-terminated tripodal derivatives 13 (Figure 5), which are suitable as a single-molecular tip for noncontact atomic force microscopy (NC-AFM). The reversible photoisomerisation of

• -resolution topographic imaging of the same sample surface by NC-AFM (Figure 6). In an extended study they synthetized an acetylene-terminated adamantane tripod, which was easily functionalized with various ligand moieties by means of click chemistry at the terminal acetylene (Figure 5). They prepared two

Virtual reality visual feedback for hand-controlled scanning probe microscopy manipulation of single molecules

• Philipp Leinen,
• Matthew F. B. Green,
• Taner Esat,
• Christian Wagner,
• F. Stefan Tautz and
• Ruslan Temirov

Beilstein J. Nanotechnol. 2015, 6, 2148–2153, doi:10.3762/bjnano.6.220

• position of the SPM tip during manipulation in real time, while simultaneously plotting the experimentally measured frequency shift (Δf) of the non-contact atomic force microscope (NC-AFM) tuning fork sensor as well as the magnitude of the electric current (I) flowing between the tip and the surface. The

• advantages of the set-up are demonstrated by applying it to the model problem of the extraction of an individual PTCDA molecule from its hydrogen-bonded monolayer grown on Ag(111) surface. Keywords: non-contact atomic force microscopy (NC-AFM); Oculus Rift; perylene-3,4,9,10-tetracarboxylic dianhydride

• commercial, combined qPlus tuning fork [4] non-contact atomic force/scanning tunnelling microscope (NC-AFM/STM) operated at 5 K under ultra-high vacuum conditions. Each extraction attempt started with positioning the tip over one of the four carboxylic oxygen atoms (marked by red circles in Figure 1) of the

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

• performed a deposition of the solvent solution only, i.e., toluene/isopropanol in the ratio 2:1 on a clean KBr(001) surface. Figure 2a shows a topography image acquired by nc-AFM at room temperature on a KBr(001) surface after a total time of 30 min of UHV-ESI deposition of the pure solvent. This is a long

• surface but are diffusing to fast for nc-AFM imaging. Large coverage UHV-ESI of triply fused diporphyrins The complex porphyrin-based molecules under study are schematically shown in Figure 3a. It is a triply fused diporphyrin molecule including two 3-cyanophenyl groups and Zn metal cores. Similar

• μL/min, a maximum applied high voltage of 1.5 kV, and a pressure in the vacuum chamber below 2 × 10−7 mbar. A topographic image acquired by nc-AFM after UHV-ESI deposition of the diporphyrin on the clean KBr(001) surface is displayed in Figure 3b. Large molecular features are homogeneously

Lower nanometer-scale size limit for the deformation of a metallic glass by shear transformations revealed by quantitative AFM indentation

• Arnaud Caron and
• Roland Bennewitz

Beilstein J. Nanotechnol. 2015, 6, 1721–1732, doi:10.3762/bjnano.6.176

• both samples non-contact (nc)-AFM imaging was used to determine the RMS-roughness Rq over a representative area of 250 × 250 nm2. For atomically flat Pt(111) we found Rq = 0.372 nm, caused by atomic steps between terraces, and for Pt57.5Cu14.7Ni5.3P22.5 metallic glass we found Rq = 0.375 nm. The

• nanometer-scale plastic deformation of Pt(111) and the Pt57.5Cu14.7Ni5.3P22.5 metallic glass was investigated in ultra-high vacuum by AFM indentation and subsequent nc-AFM imaging using a VT-AFM manufactured by Omicron Nanotechnology GmbH, Germany. In non-contact AFM an AFM cantilever is driven to oscillate

• the extension rate were varied from 1 to 8 nm/s. The plastic deformation of both sample surfaces was analyzed based on nc-AFM topographical images of the indents and on the force–distance curves recorded during AFM-indentation. Figure 1a shows a typical topographical image of a Pt(111) surface after

Nano-contact microscopy of supracrystals

• Adam Sweetman,
• Nicolas Goubet,
• Ioannis Lekkas,
• Marie Paule Pileni and
• Philip Moriarty

Beilstein J. Nanotechnol. 2015, 6, 1229–1236, doi:10.3762/bjnano.6.126

• based on a combination of STM and dynamic force microscopy (DFM) imaging and spectroscopy. DFM experiments, also known as non-contact AFM (NC-AFM), are carried out using a quartz tuning fork sensor in the qPlus geometry [16][17] to which a tip has been glued. Shifts in the resonant frequency of a tine

High sensitivity and high resolution element 3D analysis by a combined SIMS–SPM instrument

• Yves Fleming and
• Tom Wirtz

Beilstein J. Nanotechnol. 2015, 6, 1091–1099, doi:10.3762/bjnano.6.110

• per pixel ranged from 5 to 10 ms/pixel. The SPM module inside the SIMS instrument was used to perform atomic force microscopy (AFM) in non-contact mode also called nc-AFM [9]. When scanning the topography, an area four times larger than the SIMS raster image was scanned with 512 × 512 pixels

Magnetic properties of self-organized Co dimer nanolines on Si/Ag(110)

• Lisa Michez,
• Kai Chen,
• Fabien Cheynis,
• Frédéric Leroy,
• Alain Ranguis,
• Haik Jamgotchian,
• Margrit Hanbücken and
• Laurence Masson

Beilstein J. Nanotechnol. 2015, 6, 777–784, doi:10.3762/bjnano.6.80

• ]. We note that these protrusions are too large to represent individual atoms. We have recently shown that neither STM nor non-contact atomic force microscopy (nc-AFM) probes can straightforwardly resolve the inner atomic structure of the Si NRs [25]. All NRs, varying only in length, present the same

Patterning a hydrogen-bonded molecular monolayer with a hand-controlled scanning probe microscope

• Matthew F. B. Green,
• Taner Esat,
• Christian Wagner,
• Philipp Leinen,
• Alexander Grötsch,
• F. Stefan Tautz and
• Ruslan Temirov

Beilstein J. Nanotechnol. 2014, 5, 1926–1932, doi:10.3762/bjnano.5.203

• manipulation protocol that removes single PTCDA molecules from the molecular monolayer very reliably. We performed the molecular manipulation with a commercially available SPM. Our instrument, the low-temperature combined non-contact atomic force/scanning tunnelling microscope (NC-AFM/STM) from CREATEC, allows

Calibration of quartz tuning fork spring constants for non-contact atomic force microscopy: direct mechanical measurements and simulations

• Jens Falter,
• Marvin Stiefermann,
• Gernot Langewisch,
• Philipp Schurig,
• Hendrik Hölscher,
• Harald Fuchs and
• André Schirmeisen

Beilstein J. Nanotechnol. 2014, 5, 507–516, doi:10.3762/bjnano.5.59

• ) allows the imaging of surfaces with true atomic resolution and the resolution of intra-molecular structures of molecules [1]. Furthermore, the non-contact AFM (nc-AFM) technique has the capability of quantifying the interaction forces acting between the probing tip and the sample site with atomic

• precision. Recent achievements of this force spectroscopy method manifest in the identification of the chemical identity of single atoms in an alloy [2] or the measurement of the force applied during the controlled manipulation of molecules or atoms on a surface [3][4]. nc-AFM experiments at the atomic

• resolution in nc-AFM experiments. Today, many commercially available AFMs for UHV and LT conditions are based on quartz sensors because of their impressive performance and easy technical implementation. Common AFM sensors are microfabricated from silicon or silicon nitride with the tip already integrated

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

• Adam Sweetman Andrew Stannard The School of Physics and Astronomy, The University of Nottingham, Nottingham, NG7 2RD, U.K. 10.3762/bjnano.5.45 Abstract In principle, non-contact atomic force microscopy (NC-AFM) now readily allows for the measurement of forces with sub-nanonewton precision on the

• extrapolation method. Keywords: background subtraction; DFM; F(z); force; atomic resolution; NC-AFM; Si(111); STM; van der Waals; Introduction Non-contact atomic force microscopy (NC-AFM) is now the tool of choice for surface scientists wishing to investigate interatomic and intermolecular forces on surfaces

• to obtain the desired quantity. In this paper the focus primarily concerns the imaging and quantitative interpretation of atomic or molecular resolution NC-AFM experiments conducted in ultrahigh vacuum (UHV). In these experiments, the quantity of interest is usually the site-specific/short-range

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

• materials employed in electronic devices in order to optimize their performance. In this work we used NC-AFM in combination with quantitative KPFM to study the influence of the substrate material and the processing on single layer MoS2 during device fabrication. We find a strong influence of contaminations

• impact on the surface potential. Second, that by choosing appropriate materials the work function can be modified to reduce contact resistance. Keywords: KPFM; MoS2; NC-AFM; surface potential; work function; Introduction Due to their unique properties which can differ a lot compared to bulk materials

• measurements were performed under ambient conditions using amplitude modulated KPFM, both having a great impact on the results. In this work we study the work function of SLM on a standard SiO2/Si substrate using non-contact atomic force microscopy (NC-AFM) and Kelvin probe force microscopy in situ. In our

Noncontact atomic force microscopy II

• Mehmet Z. Baykara and
• Udo D. Schwarz

Beilstein J. Nanotechnol. 2014, 5, 289–290, doi:10.3762/bjnano.5.31

• achieved in 1994 with the invention of noncontact atomic force microscopy (NC-AFM). The basic idea behind NC-AFM is based on the detection of minor changes in the resonance frequency of a micro-machined cantilever carrying a sharp probe tip due to attractive force interactions while it is oscillated above

• the sample surface to be investigated. Since actual contact with the sample is avoided, the probe tip retains its sharpness and atomic-resolution images may be obtained. Since its introduction two decades ago, NC-AFM has indeed been used to image a large number of conducting, semi-conducting, and

• insulating material surfaces of technological and scientific importance with atomic resolution, thus contributing to nano-scale science in a major way with each passing year. The capabilities of NC-AFM are not only limited to atomic-resolution imaging: Force spectroscopy allows characterization of

The role of surface corrugation and tip oscillation in single-molecule manipulation with a non-contact atomic force microscope

• Christian Wagner,
• Norman Fournier,
• F. Stefan Tautz and
• Ruslan Temirov

Beilstein J. Nanotechnol. 2014, 5, 202–209, doi:10.3762/bjnano.5.22

• , and qPlus-based non-contact atomic force (NC-AFM) microscopes can be a potent tool when applied to studies of single-molecule manipulation [6][11][15]. The STM function facilitates the effective preparation of the experiment while the NC-AFM, operated simultaneously with the STM, is used to control

• -molecule junctions is still not generally understood and therefore the forces that act in the junction during the manipulation provide more direct information about the conformation of the molecule. One of the first attempts to manipulate large organic adsorbates with the tip of the LT-STM/NC-AFM has been

• . Experimental The details of PTCDA lifting experiments have been described previously [3][6][11]. Here we briefly repeat the essential features of the experimental procedure. We lift single PTCDA molecules (cf. inset of Figure 1a) from a Au(111) single crystal surface by using an LT-STM/NC-AFM from CREATEC [3

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

• oscillation was held constant at A = 0.40 nm. To avoid crosstalk between tunneling current and deflection signal, no voltage was applied to the tip during NC-AFM operation. The tip was prepared by voltage pulses and soft indentation into the Ag sample most likely resulting in a Ag-terminated apex. However, it

• effect can only be observed in the regime of repulsive forces near the minimum of the FTS(z) curves, it is not surprising that it was not observed in NC-AFM topography scans, yet. Such scans are in most cases recorded at a constant frequency shift. In the repulsive force regime (in which the repulsive

• adsorbates. (a) STM topography scan (V = 0.2 V, I = 0.3 nA) of PTCDA on Ag(111). The two molecule orientations (turquois rectangles) of the unit cell correspond to different adsorption geometries and are imaged with a different intensity. (b) NC-AFM topography scan (Δf = −0.6 Hz) of the surface area where

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

• deflection detector. Previous studies of noise propagation often retrieve the general expression of frequency noise of a thermally excited harmonic oscillator and are not specific to a PLL based setup, and furthermore, do not extend to the noise in the KFM signal. The pioneer work on nc-AFM, [3] already

• mentions frequency noise for the first time in the context of nc-AFM, but takes into account only thermal probe excitation noise. Fukuma et al. [5] performed a detailed study on optimizing the probe deflection sensor and compare the measured noise power spectral density (PSD) at the PLL frequency output to

Structural development and energy dissipation in simulated silicon apices

• Samuel Paul Jarvis,
• Lev Kantorovich and
• Philip Moriarty

Beilstein J. Nanotechnol. 2013, 4, 941–948, doi:10.3762/bjnano.4.106

• structural evolution of the tip apex within a low temperature NC-AFM experiment, we simulated a repeated tip–surface indentation until the tip structure converged to a stable termination and the characteristic hysteretic behaviour was no longer observed. Our calculations suggest that varying just a single

• rotational degree of freedom can have as measurable an impact on the tip–surface interaction as a completely different tip structure. Keywords: apex structure; atomic force microscopy; DFT; dissipation; hysteresis; NC-AFM; silicon; spectroscopy; tip structure; Introduction The theoretical treatment of

• chemical interactions at the single atom level has driven considerable progress in NC-AFM over the past decade. Through understanding the interactions between the AFM tip and sample surface, the chemical interactions present in AFM images [1][2][3][4][5], manipulation experiments [6][7][8][9][10], and

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

• mechanically exfoliated under ambient conditions on 6H-SiC(0001) are modified by (i) swift heavy ion (SHI) irradiation, (ii) by a force microscope tip and (iii) by severe heating. The resulting surface topography and the surface potential are investigated with non-contact atomic force microscopy (NC-AFM) and

• . Peeling at a folding over an edge different from a low index crystallographic direction can result in twisted BLG, showing a similar height as Bernal (or AA-stacked) BLG in NC-AFM images. The rotational stacking can be identified by a significant contrast in the local contact potential difference (LCPD

• ) measured by KPFM. Keywords: graphene; Kelvin probe force microscopy (KPFM), local contact potential difference (LCPD); non-contact atomic force microscopy (NC-AFM); SiC; Introduction Since its discovery in 2004 [1], graphene, the 2D crystal with a honeycomb lattice of sp2-bonded carbon atoms, has been

Optimal geometry for a quartz multipurpose SPM sensor

• Julian Stirling

Beilstein J. Nanotechnol. 2013, 4, 370–376, doi:10.3762/bjnano.4.43

• microscopes (AFM) and lateral force microscopes (LFM), however, the sensor is more complex. The atomically sharp probe must be combined with a force sensor, usually a cantilever, with either piezoelectric or optical deflection detection. For noncontact AFM (NC-AFM) and dynamic LFM (DLFM), where the sensor is

• ] respectively, into a wide range of specialised sensors. The most common NC-AFM sensors: silicon microcantilvers [5], and quartz sensors such as the qPlus sensor (tuning fork) [6] or KolibriSensor® [7], have all been used for combined AFM/STM [7][8][9]. Combined AFM/LFM sensors have been constructed from

• -asperity friction [12], where the relationship between normal and lateral force is of interest. In this paper, we suggest the optimum geometry of a quartz sensor to produce a combined AFM/LFM/STM from a quartz crystal resonator with many theoretical benefits over other sensors. Combining NC-AFM and DLFM

Determining cantilever stiffness from thermal noise

• Jannis Lübbe,
• Matthias Temmen,
• Philipp Rahe,
• Angelika Kühnle and
• Michael Reichling

Beilstein J. Nanotechnol. 2013, 4, 227–233, doi:10.3762/bjnano.4.23

• demonstrate that the latter method is in particular useful for noncontact atomic force microscopy (NC-AFM) where the required simple instrumentation for spectral analysis is available in most experimental systems. Keywords: AFM; cantilever; noncontact atomic force microscopy (NC-AFM); Q-factor; thermal

• force microscopy (NC-AFM) based on cantilever or tuning fork force sensors. We recently demonstrated how Equation 1 defines the ultimate limit of signal detection for an NC-AFM measurement performed under ultrahigh vacuum (UHV) conditions [6]. Although most NC-AFM systems are operated with cantilevers

• excited near their fundamental eigenfrequency f0, higher eigenmodes [7] have been investigated in the context of noise analysis [8], and it has been debated whether the thermal noise limitations in NC-AFM measurements could be reduced by operating cantilevers at higher eigenmodes [9]. It has further been

Thermal noise limit for ultra-high vacuum noncontact atomic force microscopy

• Jannis Lübbe,
• Matthias Temmen,
• Sebastian Rode,
• Philipp Rahe,
• Angelika Kühnle and
• Michael Reichling

Beilstein J. Nanotechnol. 2013, 4, 32–44, doi:10.3762/bjnano.4.4

• : SmarAct GmbH, Schütte-Lanz-Strasse 9, 26135 Oldenburg, Germany now at: Department of Physics and Astronomy, The University of Utah, 115 South 1400 East, Salt Lake City, UT 84112, USA 10.3762/bjnano.4.4 Abstract The noise of the frequency-shift signal Δf in noncontact atomic force microscopy (NC-AFM

• find an excellent agreement between the calculated and measured values for dΔf. Furthermore, we demonstrate that thermal noise in dΔf, defining the ultimate limit in NC-AFM signal detection, can be kept low by a proper choice of the cantilever whereby its Q-factor should be given most attention. A

• system with a low-noise signal detection and a suitable cantilever, operated with appropriate filter and feedback-loop settings allows room temperature NC-AFM measurements at a low thermal-noise limit with a significant bandwidth. Keywords: Cantilever; feedback loop; filter; noncontact atomic force

Characterization of the mechanical properties of qPlus sensors

• Jan Berger,
• Martin Švec,
• Martin Müller,
• Martin Ledinský,
• Antonín Fejfar,
• Pavel Jelínek and
• Zsolt Majzik

Beilstein J. Nanotechnol. 2013, 4, 1–9, doi:10.3762/bjnano.4.1

• , including biology, chemistry and physics. In particular, noncontact atomic force microscopy [3] (nc-AFM) has developed into a powerful technique for imaging with true atomic resolution [4][5], chemical sensitivity [6][7][8] or for performing single atom manipulation [9][10][11] on all types of surfaces

• , including insulators. Shortly after the invention of AFM and STM, the first attempt to combine static AFM and STM measurements was made by Dürig et al. in 1986 [12]. A few years later, combined nc-AFM/STM using a Si cantilever was reported for the first time (see [13]), showing the capability to record

Probing three-dimensional surface force fields with atomic resolution: Measurement strategies, limitations, and artifact reduction

• Mehmet Z. Baykara,
• Omur E. Dagdeviren,
• Todd C. Schwendemann,
• Harry Mönig,
• Eric I. Altman and
• Udo D. Schwarz

Beilstein J. Nanotechnol. 2012, 3, 637–650, doi:10.3762/bjnano.3.73

• , Germany Department of Chemical and Environmental Engineering, Yale University, New Haven, CT 06520, USA 10.3762/bjnano.3.73 Abstract Noncontact atomic force microscopy (NC-AFM) is being increasingly used to measure the interaction force between an atomically sharp probe tip and surfaces of interest, as a

• by using NC-AFM always reflect the properties of both the sample and the probe tip, efforts to reduce unwanted effects of the tip on recorded data are indispensable for the extraction of detailed information about the atomic-scale properties of the surface. Keywords: atomic force microscopy; force

• spectroscopy; NC-AFM; three-dimensional atomic force microscopy; tip asymmetry; tip elasticity; Introduction Experimentally obtained information about atomic-scale interactions of specific surfaces with atoms, molecules, and other surfaces in their vicinity is crucial for a number of important scientific

Models of the interaction of metal tips with insulating surfaces

• Thomas Trevethan,
• Matthew Watkins and
• Alexander L. Shluger

Beilstein J. Nanotechnol. 2012, 3, 329–335, doi:10.3762/bjnano.3.37

• . Keywords: atomic force microscopy; density functional theory; ionic surfaces; metallic asperities; surface interactions; Introduction The noncontact atomic force microscope (NC-AFM) is capable of imaging both conducting and insulating systems with true atomic resolution and has provided extraordinary

• contributions to surface science [1][2][3]. In NC-AFM the tip is prevented from jumping into mechanical contact with the sample surface due to the large restoring force of the cantilever at the turning point of the tip trajectory when it is closest to the surface. As a result, the instrument can probe all

• fact, in many cases atomic-resolution images are only obtained after the tip has been deliberately crashed into the surface, implying that the tip apex is formed from surface species [1][2]. The development of NC-AFM based on a quartz tuning fork (qPlus sensor) instead of a silicon cantilever has led

Graphite, graphene on SiC, and graphene nanoribbons: Calculated images with a numerical FM-AFM

• Fabien Castanié,
• Laurent Nony,
• Sébastien Gauthier and
• Xavier Bouju

Beilstein J. Nanotechnol. 2012, 3, 301–311, doi:10.3762/bjnano.3.34

• as dissipation [66][124][125] and the influence of noise perturbations [126]. Illustration of constant-height and constant-Δf imaging modes in nc-AFM. We consider, as an illustrative situation, the cases of a homogeneous and atomically corrugated surface with a step (a) and a heterogeneous, but still