Comparing a porphyrin- and a coumarin-based dye adsorbed on NiO(001)

• Sara Freund,
• Antoine Hinaut,
• Nathalie Marinakis,
• Edwin C. Constable,
• Ernst Meyer,
• Catherine E. Housecroft and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2019, 10, 874–881, doi:10.3762/bjnano.10.88

• investigated by Kelvin probe force microscopy (KPFM) [25]. This technique is used to observe and quantify the contact potential difference (CPD) changes between the metal oxide surface and the molecular layers and to determine the corresponding dipole moments. Results and Discussion Atomically clean NiO

• ≈ 165 kHz, quality factor Qf1 ≈ 30000) with compensated contact potential difference. Kelvin probe force microscopy was performed in frequency-modulation mode using a voltage modulation applied together with the dc compensation voltage to the sample (Vac = 800 mV and fac = 1 kHz or 250 Hz). (a

Novel reversibly switchable wettability of superhydrophobic–superhydrophilic surfaces induced by charge injection and heating

• Xiangdong Ye,
• Junwen Hou and
• Dongbao Cai

Beilstein J. Nanotechnol. 2019, 10, 840–847, doi:10.3762/bjnano.10.84

• -contact area in the coating. The surface potential was measured at five points in each sample area. The results are shown in Table 1. Because there are many KPFM images (CPD) for the whole data set in Table 1, as an example, we have only shown the KPFM image for the point 1 to show the contact potential

Review of time-resolved non-contact electrostatic force microscopy techniques with applications to ionic transport measurements

• Aaron Mascaro,
• Yoichi Miyahara,
• Tyler Enright,
• Omur E. Dagdeviren and
• Peter Grütter

Beilstein J. Nanotechnol. 2019, 10, 617–633, doi:10.3762/bjnano.10.62

• techniques have been developed aimed at measuring local electronic and ionic properties on a wide range of samples. By carefully controlling the electric field between the tip and sample many properties can be measured with high spatial resolution including static properties such as local contact potential

Nitrous oxide as an effective AFM tip functionalization: a comparative study

• Taras Chutora,
• Bruno de la Torre,
• Pingo Mutombo,
• Jack Hellerstedt,
• Jaromír Kopeček,
• Pavel Jelínek and
• Martin Švec

Beilstein J. Nanotechnol. 2019, 10, 315–321, doi:10.3762/bjnano.10.30

• spectroscopy measurements, i.e., the interaction energy toward different atomic species in force spectroscopy, the contact potential difference in Kelvin probe force microscopy (KPFM) [9][29] and vibrational levels of inelastic tunneling spectroscopy (IETS) [30][31]. A particular termination of the tip may be

Electrostatic force microscopy for the accurate characterization of interphases in nanocomposites

• Diana El Khoury,
• Richard Arinero,
• Jean-Charles Laurentie,
• Mikhaël Bechelany,
• Michel Ramonda and
• Jérôme Castellon

Beilstein J. Nanotechnol. 2018, 9, 2999–3012, doi:10.3762/bjnano.9.279

• applied voltages, respectively, and VCP is the contact potential difference; qt is expressed as follows: where qDC = CVDC, qAC = CVACsin(ωt) and qCP = CVCP are the capacitive charges due to VDC, VACsin(ωt) and VCP, respectively. Consequently, the development of Equation 1 shows that the force, and hence

In situ characterization of nanoscale contaminations adsorbed in air using atomic force microscopy

• Jesús S. Lacasa,
• Lisa Almonte and
• Jaime Colchero

Beilstein J. Nanotechnol. 2018, 9, 2925–2935, doi:10.3762/bjnano.9.271

• function of tip–sample voltage and tip–sample distance, we are able to determine the contact potential, the Hamaker constant and the effective thickness of the dielectric layer within the tip–sample system. All these properties depend strongly on the contamination within the tip–sample system. We propose

• to access the state of contamination of real surfaces under ambient conditions using advanced atomic force microscopy techniques. Keywords: atomic force microscopy; cantilever; contact potential; electrostatic forces; force spectroscopy; Hamaker constant; Kelvin probe microscopy; surface

• of contamination as the rest of the cantilever and as the chip onto which the tip and cantilever are attached. Second, we will assume that by precisely measuring the tip–sample interaction we can infer properties related to the surface energy as well as the contact potential, which allows one to

A scanning probe microscopy study of nanostructured TiO₂/poly(3-hexylthiophene) hybrid heterojunctions for photovoltaic applications

• Laurie Letertre,
• Roland Roche,
• Olivier Douhéret,
• Hailu G. Kassa,
• Denis Mariolle,
• Nicolas Chevalier,
• Łukasz Borowik,
• Philippe Dumas,
• Benjamin Grévin,
• Roberto Lazzaroni and
• Philippe Leclère

Beilstein J. Nanotechnol. 2018, 9, 2087–2096, doi:10.3762/bjnano.9.197

• , conductive Nanosensors PPP-EFM tips (PtIr-coated Si probes) were used (resonant frequency around 75 kHz). The sample was grounded while the excitation and regulation biases were applied to the tip. The measured contact potential difference (Vcpd) is given by the following expression: where Φtip and Φsample

Recent highlights in nanoscale and mesoscale friction

• Andrea Vanossi,
• Dirk Dietzel,
• Andre Schirmeisen,
• Ernst Meyer,
• Rémy Pawlak,
• Thilo Glatzel,
• Marcin Kisiel,
• Shigeki Kawai and
• Nicola Manini

Beilstein J. Nanotechnol. 2018, 9, 1995–2014, doi:10.3762/bjnano.9.190

• to be proportional to (V − Vcpd)2, where V is the tip–substrate bias voltage and Vcpd is the contact potential difference, whereas the phononic contribution is proportional to (V − Vcpd)4 [193]. Park et al. observed the influence of electronic friction on semiconductive surfaces in contact mode and

Numerical analysis of single-point spectroscopy curves used in photo-carrier dynamics measurements by Kelvin probe force microscopy under frequency-modulated excitation

• Pablo A. Fernández Garrillo,
• Benjamin Grévin and
• Łukasz Borowik

Beilstein J. Nanotechnol. 2018, 9, 1834–1843, doi:10.3762/bjnano.9.175

• contact potential difference (CPD) under continuous wave illumination (or DC bias excitation) can give us the magnitude of the average potential that we should detect for the highest modulation frequency if the SPV built-up time can be approximated to zero. In this scenario, data can be fitted assuming τb

Know your full potential: Quantitative Kelvin probe force microscopy on nanoscale electrical devices

• Amelie Axt,
• Ilka M. Hermes,
• Victor W. Bergmann,
• Niklas Tausendpfund and
• Stefan A. L. Weber

Beilstein J. Nanotechnol. 2018, 9, 1809–1819, doi:10.3762/bjnano.9.172

• modulation (AM) and frequency modulation (FM) Kelvin probe force microscopy (KPFM) methods under ambient conditions to investigate how these methods can measure quantitative variations in the local contact potential difference (CPD). KPFM is a scanning force microsopcy (SFM) method that correlates the local

• applying an additional DC voltage UDC to the tip, the electrostatic force is minimized if UDC = UCPD, where UCPD is the contact potential difference between the tip and the sample. This is the basic operation principle of KPFM [31]. This section will introduce the operation principles of the AM- and FM

Multimodal noncontact atomic force microscopy and Kelvin probe force microscopy investigations of organolead tribromide perovskite single crystals

• Yann Almadori,
• David Moerman,
• Jaume Llacer Martinez,
• Philippe Leclère and
• Benjamin Grévin

Beilstein J. Nanotechnol. 2018, 9, 1695–1704, doi:10.3762/bjnano.9.161

• of nanometers. KPFM measurements were carried out in single-pass mode under frequency modulation (FM-KPFM) with the modulation bias, VAC (typically 0.5 V peak-to-peak at 1200 Hz), and the compensation voltage, VDC, applied to the cantilever (tip bias Vtip = VDC). The contact potential difference (CPD

Electrostatically actuated encased cantilevers

• Benoit X. E. Desbiolles,
• Gabriela Furlan,
• Adam M. Schwartzberg,
• Paul D. Ashby and
• Dominik Ziegler

Beilstein J. Nanotechnol. 2018, 9, 1381–1389, doi:10.3762/bjnano.9.130

• charging states in the encasement material, the electrical contact potential or any other static offsets. Not requiring any dc voltage greatly reduces the risk of electrolytic production of gas bubbles. Electrostatic actuation in encased cantilevers provides more gentle imaging and more reliable

• in Figure 2b,c are recorded using harmonic excitation, where the excitation frequency ωel matches the resonance frequency of the cantilever (ω0). As introduced above, the electrostatic force is given by Fel = (1/2)C′U2. The electrical potential difference U is composed of Udrive and the contact

• potential difference UCPD between cantilever and drive electrode. The drive voltage is Udrive = Uac sin(ωelt) + Udc, where ωel = 2πfel is the angular frequency, fel is the frequency and t is the time. The resulting electrostatic force Fel exhibits three spectral components as follows Figure 3a shows the

Artifacts in time-resolved Kelvin probe force microscopy

• Sascha Sadewasser,
• Nicoleta Nicoara and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2018, 9, 1272–1281, doi:10.3762/bjnano.9.119

• nanometer scale [2]. The imaging mechanism relies on the compensation of electrostatic forces by application of a bias voltage that corresponds to the local contact potential difference (CPD), the relative difference between the work function of the tip and that of the sample area below the tip. In most

• -detection voltage and VCPD the contact potential difference. In our numerical simulations, no z feedback is considered and the z position of the cantilever tip is only influenced by electrostatic forces. This was done in order to focus on the effect of the electrostatic forces. To realize time-resolved KPFM

• that corresponds to the contact potential difference (CPD). The topography control (z feedback) was normally realized on the fundamental resonance of the cantilever. However, in some experiments the z feedback and the cantilever oscillation were switched off during the pulse sequences and the tip was

Nanoscale mapping of dielectric properties based on surface adhesion force measurements

• Ying Wang,
• Yue Shen,
• Xingya Wang,
• Zhiwei Shen,
• Bin Li,
• Jun Hu and
• Yi Zhang

Beilstein J. Nanotechnol. 2018, 9, 900–906, doi:10.3762/bjnano.9.84

• CRGO. That is, GO and CRGO in the mixed sample can be distinguished clearly by this method. It is worth noting that the contact potential differences between the AFM tip and GO/RGO are about three orders of magnitude lower than the tip bias in adhesion mapping (Supporting Information File 1, Figure S1

• ). So the effect of the contact potential difference between the tip and our sample was ignored in our experiments. A comparison study of dielectric property mapping by adhesion force and SPFM was also carried out. Figure 3g shows an in situ SPFM image of Figure 3c taken with an AFM tip biased at 10 V

Combined pulsed laser deposition and non-contact atomic force microscopy system for studies of insulator metal oxide thin films

• Daiki Katsube,
• Hayato Yamashita,
• Satoshi Abo and
• Masayuki Abe

Beilstein J. Nanotechnol. 2018, 9, 686–692, doi:10.3762/bjnano.9.63

• shift were f0 = 167 kHz, k = 34.9 N/m, A = 14 nm, Δf = −4.2 Hz for (a), and f0 = 164 Hz, k = 32.9 N/m, A = 16 nm, Δf = −13 Hz for (b), respectively. The contact potential difference (CPD) was compensated for each image with Vs = 2.5 V for (a) and Vs = −0.6 V for (b). The substrates used for PLD were Nb

• annealing for imaging with atomic resolution. We confirmed that this is the case for the anatase TiO2(001) thin film, but not for LaAlO3(100). However, even if one can obtain atomic-resolution images, the influence on the surface by, e.g., OH groups, cannot be completely eliminated. Furthermore, the contact

• potential difference (CPD) of the insulator surface synthesized with our PLD system is at most about 3 V. With our system, it is possible to measure without affecting the charging of the sample surface, which often occurs on insulator surfaces. Conclusion We have developed a combined system of NC-AFM and

Anchoring of a dye precursor on NiO(001) studied by non-contact atomic force microscopy

• Sara Freund,
• Antoine Hinaut,
• Nathalie Marinakis,
• Edwin C. Constable,
• Ernst Meyer,
• Catherine E. Housecroft and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2018, 9, 242–249, doi:10.3762/bjnano.9.26

• ] direction in the second (orientation H). The heights of 180 ± 20 pm of both arrays suggest that the molecules are still lying flat on the surface in the same configuration as described above, independently of the island orientation. Figure 5b shows the contact potential difference (CPD) simultaneously

• ), using silicon cantilever (Nanosensors PPP-NCR, stiffness k = 20–30 N/m, resonance frequency f1 around 165 kHz, Qf1 factor around 30000, torsional frequency fTR around 1.5 MHz, and QTR factors around 100000) with compensated contact potential difference (CPD). Kelvin probe force microscopy was performed

Combined scanning probe electronic and thermal characterization of an indium arsenide nanowire

• Tino Wagner,
• Fabian Menges,
• Heike Riel,
• Bernd Gotsmann and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2018, 9, 129–136, doi:10.3762/bjnano.9.15

• voltage applied to the tip [14]. The resulting local contact potential difference, Ulcpd, depends on the work functions of tip and surface, voltages applied to tip and sample, and charges trapped inside insulators. In two-terminal devices, the voltage profile induced by a constant current bias can be

Analysis and modification of defective surface aggregates on PCDTBT:PCBM solar cell blends using combined Kelvin probe, conductive and bimodal atomic force microscopy

• Hanaul Noh,
• Alfredo J. Diaz and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2017, 8, 579–589, doi:10.3762/bjnano.8.62

• energy band bending. (a) Electrostatic potential distribution in space between the tip (red) and bottom electrode. (b) Calculated energy diagram along the shortest path from the tip end to the bottom electrode showing the built-in contact potential difference and band bending. Solid black and dotted blue

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

• investigated in dark conditions and upon illumination. The topographic and contact potential difference (CPD) images taken under dark conditions are analysed in view of the results of complementary transmission electron microscopy (TEM) experiments. After in situ annealing, it is shown that the dyads with

• contact potential difference (CPD) is equal to −VDC. In this work, the potentiometric data are presented as compensation bias (Vtip = −CPD) images (also called CPD images, KPFM potential or surface potential images). Surface photo-voltage (SPV) images were calculated as the difference between the

• doubling of the lamellar periodicity. They may exist either as small face-on domains or inclined lamellae. Electrostatic contrasts under dark conditions Further insight into the structural organization can be achieved by analysing the contact potential images in dark conditions (Figure 6a). In principle

Large area scanning probe microscope in ultra-high vacuum demonstrated for electrostatic force measurements on high-voltage devices

• Urs Gysin,
• Thilo Glatzel,
• Thomas Schmölzer,
• Adolf Schöner,
• Sergey Reshanov,
• Holger Bartolf and
• Ernst Meyer

Beilstein J. Nanotechnol. 2015, 6, 2485–2497, doi:10.3762/bjnano.6.258

• the benefit of surface photo voltage measurements, we analysed the contact potential difference of a silicon carbide p/n-junction under illumination. Keywords: copper alloy; electrostatic force microscopy; high-voltage device; Kelvin probe force microscopy; silicon carbide (SiC); surface photo

• measurement of the surface photo voltage (SPV) in dependence on the wavelength and light intensity via measuring of the contact potential difference (CPD) values in the dark as well as under illumination [25]. In the second part we present several studies highlighting the potential of the novel instrument

• distinguish between different materials in metallic or differently doped regions in semiconductors several scanning probe microscopy methods are implemented in our novel microscope. KPFM measures the difference of the contact potential difference (CPD) between the tip and the sample by applying a dc voltage

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

• lateral resolution and pronounced capacitive averaging of the locally measured contact potential difference. Furthermore, local changes in the strength of the electrostatic interaction between tip and surface easily lead to topography crosstalk seen in the surface potential. To take full advantage of the

• electric field by adjusting a bias voltage between tip and sample. Hence, Kelvin probe force microscopy is able to quantify the local contact potential difference (CPD), Ulcpd, which contains contributions, e.g., from the difference in work function between the AFM tip and structures on the sample, dopants

• modulated electrostatic force. Hence, the KFM image is a map of voltages required to compensate the electrostatic force at every point of the scanned field. However, since cantilever and AFM tip are extended objects, this voltage does not necessarily correspond to the local contact potential difference

Graphene on SiC(0001) inspected by dynamic atomic force microscopy at room temperature

• Mykola Telychko,
• Jan Berger,
• Zsolt Majzik,
• Pavel Jelínek and
• Martin Švec

Beilstein J. Nanotechnol. 2015, 6, 901–906, doi:10.3762/bjnano.6.93

• the shape nor in their maxima. The contact potential between the tip and the sample corresponds to maxima in the parabolas and is located at −0.32 eV. In Figure 3, the Δf and maps are presented for the same area of the sample, taken in a constant height regime with a slow feedback setpoint at

• detect any significant contact potential difference between the dark and bright protrusions of the q-6 modulation. It can be understood as a negligible workfunction difference between these investigated areas. Conclusion In summary, we successfully probed the epitaxial graphene on SiC(0001) by a combined

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

• and non-polar liquids), KPFM and EcFM are both feasible, yielding comparable contact potential difference (CPD) values. In ionically-active liquids, KPFM is not possible and EcFM can be used to measure the dynamic CPD and a rich spectrum of information pertaining to charge screening, ion diffusion

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

• 7500 system with the PLL Pro 2 controller. Simultaneously to NC-AFM, frequency-modulated KPFM measurements were conducted to probe the local contact potential difference (CPD) between the tip and the surface [35][36][37][38][39][40][41]. As force sensors, highly conductive Si cantilevers with a typical

• observed. It has been shown by Castellanos-Gomez et al. that heavy strain in SLM has a large impact on the band gap of SLM [59]. However, KPFM only measures the contact potential difference (from which we derive the work function). For insulating materials there is no straightforward relation between the

• contact potential difference and the band-gap. Therefore, our results are not directly comparable. The plot in Figure 5c sums up our findings with respect to the work function of MoS2. The work function of FLM in ambient has been determined previously by amplitude modulated KPFM. The reported values of Φ

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

• cutoff frequency of the distance controller, but below the cutoff frequency of the PLL. The contact potential difference (CPD) between tip and sample is indicated by a voltage applied to the sample. It may be due to a work function difference between the sample and the tip or due to a sample to which a