Advanced atomic force microscopies and their applications in two-dimensional materials: a review
doi: 10.1088/2752-5724/ac8aba
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Abstract: Scanning probe microscopy (SPM) allows the spatial imaging, measurement, and manipulation of nano and atomic scale surfaces in real space. In the last two decades, numerous advanced and functional SPM methods, particularly atomic force microscopy (AFM), have been developed and applied in various research fields, from mapping sample morphology to measuring physical properties. Herein, we review the recent progress in functional AFM methods and their applications in studies of two-dimensional (2D) materials, particularly their interfacial physical properties on the substrates. This review can inspire more exciting application works using advanced AFM modes in the 2D and functional materials fields.
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Figure 2. (a) Qualitative behavior of the force between tip and sample as a function of tip-sample distance. (b) and (c) Schematics of atomic force microscopy (AFM) operation: (b) contact mode (static mode), and (c) amplitude modulation mode in dynamic mode. (d) Schematic of frequency modulation detection setup operated in the self-excitation mode. Non-contact AFM.
Figure 3. (a) Scanning electron microscopy (SEM) image of a micromachined silicon cantilever with an integrated tip pointing in the [001] crystal direction. (b) Micrograph of a qPlus’sensora cantilever made from a quartz tuning fork [12]. (c)-(f) SEM images of some typical commercial AFM probes: (c) Silicon probe suitable for contact mode. (d) Super sharp silicon probe, suitable for non-contact and tapping modes. (e) High aspect ratio tip. (f) Pyrex-nitride probe. (NanoWorld & PointProbe AFM tip). Reproduced from [12]. © IOP Publishing Ltd. All rights reserved.
Figure 5. Sketch map of (a) friction force microscopy (FFM) and (b) transverse shear microscopy (TSM). For FFM (TSM), the scan direction of the AFM tip is perpendicular (parallel) to the long axis of the cantilever. The friction (shear) property of the sample is obtained by detecting the cantilever torsion signal.
Figure 6. (a) Schematic of the multi-harmonic AFM mode. Recording higher harmonic components introduced by the nonlinearity of tip-sample interaction forces during conventional dynamic AFM imaging while driving the cantilever at its first resonance mode. (b) Schematic of the dual AC AFM mode. The cantilever is simultaneously driven at two eigenmodes (resonant modes), and the amplitude and phase are recorded. (c) SEM images of the original and 6th harmonic probes. (d) Frequency response spectroscopy of the original and 6th harmonic cantilever obtained with the thermal noise spectrum measurement. (e) Frequency response spectroscopy of the AC240 probe obtained with the thermal noise spectrum measurements. (f) Resonance frequencies of the three AFM probes at the first and second resonance mode. Reproduced from [73], with permission from Springer Nature.
Figure 7. Schematic and mechanical model of contact resonance atomic force microscopy (CR-AFM) and related definitions and characterization of the cantilever used in the experiments for quantitative analysis. (a) Schematic of the CR-AFM experimental setup. (b) Tip-sample contact is modeled as a Kelvin-Voigt mechanical equivalent, where the spring and dashpot represent the contact stiffness (elastic modulus) and viscoelasticity (dissipation), respectively. (c) Close-up view of the tip-sample contact and definitions for quantitative characterization. (d) SEM characterization of the AFM cantilever and tip. Reproduced from [76], with permission from Springer Nature.
Figure 8. Electronic energy levels between the AFM tip-sample demonstrating the working principle of scanning Kelvin probe microscopy. (a) Tip-sample are separated by a distance d with no electrical contact due to the equal Evac but different EF level. (b) Tip-sample are in electrical contact and electron transfer from the sample with higher EF to the one with lower EF. (c) DC voltage VDC applied between tip-sample readjusts the vacuum level. Reproduced from [91], with permission from Springer Nature.
Figure 9. (a) Schematic of the basic setup for scanning Kelvin probe microscopy (SKPM) technique.
e is the angular frequency of the applied AC voltage and r is the resonant angular frequency of the cantilever. (b) Drawing map of two scan passes named nap mode. In the first scan, the morphological image is captured using mechanical excitation of the cantilever. The surface potential mapping is acquired in the second scan. The electronic circuit diagram of the first and second scans is given by the black and purple lines. Reproduced from [91], with permission from Springer Nature. Figure 10. Schematic of multi-harmonic electrostatic force microscopy (MH-EFM). (a) Schematic of MH-EFM experimental setup. A metal-coated tip was used. Two scan passes are needed in this technique. In the first pass, the resonant frequency amplitude of probe fr is used as feedback to obtain the sample topography. In the second pass (lift mode), an AC bias voltage within the kHz frequency (f) is applied between the tip and sample, and feedback is removed. The amplitude of cantilever vibration at f, f2, and f3 are obtained by Lock-in amplifiers A, A2, and A3, respectively. A is proportional to SP, while A2 is related to the dielectric constant. The amplitude A3 corresponds to the sample carrier concentration. (b) Response of static charges to the charged tip. (c) Response of mobile charges to the charged tip. (d) Relationship between A2, mobile charge carriers, and band gap Egap. Reproduced from [91], with permission from Springer Nature.
Figure 11. (a) Schematic of sMIM setup. The shielded probe is connected to a microwave source (GHz frequency band). Microwave transmitted into the probe has near-field interactions with the sample, while the reflected microwave is backtracked. The reflected signal is suppressed by the common-mode cancellation through a directional coupler (D), amplified by radio frequency amplifiers (A), and then demodulated by a quadrature mixer (M1). sMIM-Im and sMIM-Re information can be obtained. The signal is further modulated by quadrature mixer M2, and dC/dV and dR/dV are obtained. Inset: schematic of lumped element model. (b) The close-up Schematic of the sMIM probe. (c) The left panels are cross-sectional views and the right panels are top views of the cantilever. (d) Front-view (tip side) of the probe and cross-sectional views of the cantilever (A-A’) and tip apex (B-B’). (e), (f) SEM image of sMIM cantilever and tip. The microwave signal was transmitted to the tip through the electrode, marked in (b), to the tip apex. Reproduced from [115]. © IOP Publishing Ltd. CC BY 3.0.
Figure 12. Setup of an AFM-based scanning thermal microscopy (SThM) system. A thermal control unit delivers the output signal Vout and a balanced Wheatstone bridge maintains the probe mean temperature at a constant value [129]. John Wiley & Sons. [© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim].
Figure 13. (a) Schematic of the experimental setup for the null-point SThM. (b) SEM images of the SThM probe. Diameter of the thermocouple junction integrated at the apex of the tip is approximately 100 nm, and the tip radius is approximately 50 nm. (c) Principle of quantitative thermal profiling. (d) As the tip approaches the sample, the tip temperature rises gradually due to the heat transfer through the air. When the tip contacts the sample, the tip temperature jumps from Tnc to Tc due to the heat flux through the tip-sample contact. (e) Temperature jumps at different sample temperatures. The slope of the graph, kslope, is 10.9 K K-1 for this particular probe. Reprinted from [141], with the permission of AIP Publishing. Reprinted with permission from [143]. Copyright (2011) American Chemical Society.
Figure 14. (a) SEM image of a doped silicon probe. (b) Schematic of the principle of thermal probe. (c) Circuit diagram of the local thermal analysis module. (d) Probe electric resistance (Rprobe) vs. temperature (Tprobe = Tprobe-Tair) curve. (e) Demonstration of the thermal tip-sample approach curve. (f) Thermal conductivity (the reciprocal of thermal resistance) vs. tip voltage curve. Thermal conductivity (resistance) is negatively (positively) correlated with the probe voltage. Reproduced from [53] with permission from the Royal Society of Chemistry.
Figure 15. Strain-engineered transition metal dichalcogenides (TMDCs) using the thermal expansion coefficient (TEC)-mismatch. (a)-(c) Process schematic through which 2D materials realize strain via the TEC-mismatch between the substrate and TMDC. (a) Tensile strain is achieved when the substrate TEC is less than that of the 2D material, (b) relaxed samples are achieved when the TEC of the substrate and 2D material match, and (c) compressive strain is achieved when the substrate TEC is greater than that of the 2D material. Reprinted with permission from [154]. Copyright (2022) American Chemical Society.
Figure 16. (a) Top (upper panel) and side (lower panel) views of a 2D film at a mesoscopic scale where the edges are identically treated, showing a six-fold symmetry (see cartoon eyes and arrows). (b) Corresponding top and side views at the atomic scale show two completely distinctive edges and a three-fold symmetry. (c), (d) Typical optical and AFM topography of WS2 layer on SiO2/Si substrate. (e) Corresponding local SP images using SKPM. (f) Mobile charge carrier density (MCD) image of WS2 taken in dual harmonic-EFM (DH-EFM). (f) Friction force image of WS2 flakes. Reprinted with permission from [151]. Copyright (2020) American Chemical Society.
Figure 17. Mechanical properties of hexagonal WS2 flakes. (a) Young’s modulus calculated by Density Function Theory (DFT). (b) AFM topography of the WS2 layer on the SiO2/Si substrate. (c) Close-up AFM topography of the central area of the WS2 layer. (d) Sketch map of contact resonance mode. (e), (f) Elastic modulus and (e) energy dissipation (f) in CR mode. The corresponding topography is shown in (c). (g) Sketch map of FFM. (h), (i) Friction force image of WS2 flakes. The corresponding topography is shown in (b) and (c). Differences in the mechanical property of ZR and KR stem from the C3 atomic arrangement and inherent non-equivalence at the KR and ZR triangle vertexes. Reprinted with permission from [151]. Copyright (2020) American Chemical Society.
Figure 18. Sample preparation of triangular MoS2 flakes and the introduction of tensile strain. (a) Schematic of traditional low-pressure chemical vapor deposition (CVD) growth process. (b) Introduction of tensile strain applied by the underlying substrate during the fast-cooling process. (c), (e) Size-dependent large-scale optical images of (c) sharp-corner and (e) vein-like MoS2 flakes. (d) Statistical results of the measured sharp-corner and vein-like MoS2 flake size. Optical images of (f) and (g) sharp-corner MoS2 flake and (h) and (i) vein-like MoS2 flake. Scale bars: (c) and (e) 30
m; (f)-(i) 5 m. Reproduced from [153]. © IOP Publishing Ltd. All rights reserved. Figure 19. (a)-(d) Strain-engineered structures and properties. (a) AFM topography, (b) FFM friction, (c) mobile charge density and (d) sMIM images of sharp-corner MoS2 flake on the SiO2/Si substrate. (e) AFM topography, (f), (g) FFM friction, (h) mobile charge density image of vein-like MoS2 flake on the SiO2/Si substrate. Scale bars: (a)-(c) 6
m; (d) 2 m; (e) 5 m; (f) 8 m; (g) 3 m; (f) 5 m. Reproduced from [153]. © IOP Publishing Ltd. All rights reserved. Figure 20. (a) Photoluminescence (PL) intensity maps of triangular WS2 monolayers of lateral sizes from 6 to 45
m. Reprinted with permission from [158]. Copyright (2016) American Chemical Society. (b) AFM image of a typical triangular WS2 flake on SiO2/Si substrate. The sample was prepared by CVD and underwent a fast = cooling process. (c) KPFM SP map of the triangular WS2 flake in panel (b). Reprinted from [162], with the permission of AIP Publishing. Figure 21. (a) As-grown sample rapidly cooled to room temperature (25 C) from the growth temperature to introduce uniform strain into the sample. (b) von Mises stress of the WS2 flake with the hexagon nucleation center simulated using finite element analysis (FEA). The black lines in (b) are stress isolines, almost perpendicular to the boundary edge. (c), (d) Optical and AFM topography of the six-splitting WS2 layer on the SiO2/Si substrate. (e) MCD image of the WS2 using DH-EFM. Reprinted with permission from [154]. Copyright (2022) American Chemical Society.
Figure 22. (a) Schematic shape evolution of MoS2 flakes with various S/Mo ratios and growth temperatures. (b)-(h) Optical topographic images of a series of triangular flakes with multi-apex corners. (j), (k) Friction and (l) MCC images of the MoS2 flake with small dual-apex corners. The corresponding optical image is in (d). (m), (n) Frictional and (o) MCC images of the MoS2 flake with larger dual-apex corners. The corresponding optical image is in (e). Reprinted from [17], with the permission of AIP Publishing.
Figure 23. Formation mechanism of hierarchal ripple structures. (a)-(d) FFM images of the hierarchical ripple structures in MoS2 with different opening angles. (e)-(h) Evolution of hierarchal ripples in a silk curtain when the confined edges are gradually bent. These ripples are generated through the longitudinal tensile strains applied by the gravity of itself. (i)-(l) Schematic for elucidating the formation and evolution of hierarchical ripples. Reprinted from [17], with the permission of AIP Publishing.
Figure 24. (a) Schematic for TSM and stress distribution originating from stretch deformation. Friction can drive the stretch deformation of a film, and the TSM signals originate from the noncollinearity between the stretch force and deformation direction. If there is strain-induced anisotropic shear deformation, TSM signals will not be zero. (b) Optical image, (c) AFM topography, (d) FFM image, and (e) TSM image of a star-shaped monolayer MoS2 flake sample. In (e), (f), crystallographic labels for AC and ZZ orientations. Every domain of star-shaped monolayer MoS2 is given an identifier from P1 to P7. (g) Shear signal vs. rotation angle curves obtained by randomly selecting P5 domains with the SiO2/Si substrate. (h) Scatterplot diagram of shear signal vs. crystallographic orientation using the AC orientation as the reference direction of 0. All the data points are translated into one period of 60. Reprinted from [18], with the permission of AIP Publishing.
Figure 25. (a), (b) Schematic of the puckering effect occurring on the top layer (TL) of MoS2 rather than the bottom layer (BL). (c) Optical, (d) AFM topograp, (e) FFM, and (f) TSM images of bilayer MoS2 on the SiO2/Si substrate. The different MoS2 grains are marked as P11 and P12 for the bottom monolayer and P21 and P22 for the top layer. P0 is the amorphous SiO2/Si substrate. Reproduced from [19], with permission from Springer Nature.
Figure 26. (a) Schematic of CVD growth and cooling process. The in-plane strain is applied onto the WS2 flake via the underlying amorphous SiO2/Si substrate. (b) Optical and (c) AFM topography images of the WS2 flake, scan size: 25
m 25 m. The cyan line shows the height of the WS2 monolayer flake. (d) FM and (e) TSM images of the WS2 flake. The three rippling domains were marked I, II, and III. Reprinted with permission from [156]. Copyright (2021) American Chemical Society. Figure 27. Manipulation of ripple orientation on the monolayer WS2 flake. (a)-(c) TSM images of single rippling domain in the monolayer WS2 flake. The insets show the AFM manipulation directions and schematic of the ripple lines in the WS2 flake. In (a), three straight zigzag edges, labeled y (yellow), b (brown), and p (purple), are parallel to the ripple direction in domains I, II, and III, respectively. (d) Schematic illustrating the three rippling domains with the ripple line orientated along the zigzag crystallographic direction of WS2. (e) Schematic of the AFM manipulation directions for the ripple transformation from II and III to I. (f) TSM image of WS2 monolayer flake with single rippling domain. Three sequential TSM images show the AFM manipulation process in the WS2 flake in (f). White arrows illustrate the corresponding writing direction. (g) Snowman’ rippling domain pattern formed by the home-modified AFM lithography. The setpoint (i.e. loading force) of the contact AFM scanning is pixel-dependent according to the pre-defined grayscale image. Reprinted with permission from [156]. Copyright (2021) American Chemical Society.
Figure 28. Fracture induced by nanoscratch on single-layer MoS2. (a) Schematic of nanoscratch using AFM. The apex radius of 10 nm was chosen, which is not too sharp to pierce the film easily nor too blunt to peel such a huge film. (b) Optical image of MoS2 film after scratch. (c) FFM image of the scratched domain with distinctive crack morphology. Normal load increases from 50 to 70
N. (d), (e) Close-up of the domain in white dashed frame in (c). In (d), periodical zigzag cracks along the scratch path. In (e), the forepart of the whole fracture. (f) FFM image of a string of cracks along the armchair direction. The scratch is from left to right, as shown by the arrow. The head shape of the crack is flat. (g) String of cracks along the zigzag direction, from up to down. The head shape of the crack is angular. Reproduced from [177]. © IOP Publishing Ltd. All rights reserved. In (c)-(e), scale bars here are 1.0 m. In (f), (g), scale bars here are 0.5 m. Figure 29. (a) Schematic of the friction process and KPFM measurement system. KPFM image of graphene (b) before and (c) after rubbing. (d) Potential difference generated by tunneling triboelectrification, VTT, along the blue dashed line in (c) after 0 and 72 h; VTT is well preserved even after 72 h. (e) VTT as a function of time. The best fit (blue line) is the sum of two decaying exponential terms, each with its own time constant. Reproduced from [182]. CC BY 4.0.
Figure 30. (a) Schematic of charge transfer with tip and MoS2/SiO2 contacting. (b) Profiles of SP vs. time. (c) Schematic of charge transfer between the tip and MoS2/SiO2 with tip friction on MoS2/SiO2. (d) Profiles of SP vs. time. (e) MoS2 SP before charging. Contact voltages applied by the AFM tip are marked. (f)-(i) Series of SP images taken in the same region after biased tip contacting MoS2. (e)-(i) Scale bars are 5
m. (j) AFM topography of MoS2 on SiO2/Si substrates after rubbing. Rubbed area is marked. (k) SP images of the neutral sample. (l)-(n) AFM images of MoS2 layer after triboelectrification, showing a sharp edge between rubbed (marked R) and intact (marked I) MoS2. (j)-(m) Scale bars are 4 m. Reproduced from [30]. © IOP Publishing Ltd. All rights reserved. Figure 31. (a) Charge transfer between the 2D metal layer and insulator. (b), (c) AFM topography and SP of NbS2/BN using SKPM. Inset: SP profiles along dash lines in (c). (d) Schematic of post-exposed h-BN surface preparation. Post-exposed h-BN surface is the h-BN surface covered by NbS2 in the growth process but exposed after peeling the NbS2 using AFM tips. NbS2 layers framed by the dashed box stand for the stripped part before peeling. Charge distribution at the 1L-NbS2/BN interface and post-exposed h-BN surface is also shown. (e) AFM topography after partly peeling NbS2, the dash hexagon shows the position of the NbS2 layer before peeling. (f) SP image of the post-exposed h-BN surface. Inset: SP profiles along the dash lines in (f). (g) Schematic energy band diagram of NbS2/BN showing electron transfer from 1L-NbS2 to h-BN. Scale bars are 1
m. Reproduced from [92]. © IOP Publishing Ltd. All rights reserved. Figure 32. (a) AFM and (b) KPFM images of the MoS2/PbI2 heterostructures. (c) Schematic of band energy of MoS2/PbI2 heterostructures. Reproduced from [185], with permission from Springer Nature.
Figure 33. (a), (b) Topography and friction images (11
m 24 m) of water-intercalated graphene on mica after mechanical cleavage in air. (c), (d) Magnified topography and friction images (7 m 7 m) from the blue box in (b), where the labels represent a bare mica, b SLG, c SLG + 1 W, d BLG + 1 W, e BLG, f SLG, and g bare mica. (e), (f) Section line of the height and friction along the red lines in (c) and (d). (g) Schematic showing the variable friction behavior using an AFM tip, depending on the sublayer composition. Labels (a)-(g) in the tips match areas (a)-(g) in (c). Reproduced from [190], with permission from Springer Nature. Figure 34. (a)-(d) Recorded in-situ AFM height images of graphene supported on SiO2/Si substrate from room temperature (25 C) to 100 C. The scale bars are 2
m. (e) Magnified AFM height image and (f) corresponding SP recorded by SKPM at 80 C. The scale bars are 1 m. (g) Height and (h) VCPD line profiles measured along the yellow and red dashed lines marked in (e) and (f), respectively. Reproduced from [191] with permission from the Royal Society of Chemistry. Figure 35. (a) Optical microscopic image of the mechanically exfoliating folding few-layers graphene flake on SiO2/Si substrate. It can encapsulate water molecules because of its mechanical strength and chemical stability. (b) Basic principle of MF-AFM. The MF-AFM amplitude (AMF) reflects the local mechanical properties (e.g. elastic modulus and viscoelasticity) of the sample and has subsurface detection capability. MF-AFM observes the different phase structures of intercalated water layers. (c), (d) Topography and A6th image of water intercalated sample in multi-harmonic mode. Scan size: 30
m. (e) Histogram distribution of A6th/elastic modulus extracted from (d). Arbitrarily units (a.u.) qualitatively describe A6th/elastic modulus of the interfacial water layer. (f), (g) Topography and A2 image of the water intercalated sample in dual AC mode. Scan size: 15 m. (h) Histogram distribution of A2/dissipation extracted from (g). Reproduced from [73], with permission from Springer Nature. Figure 36. (a)-(d) Water molecules intercalate at the interface and grow on the sample surface. (e) Section lines during (blue line) and after (red line) water intercalation. (f) Schematic of evolution process and structure diagram of water molecule intercalation at the 1L-NbS2/BN heterointerface. (g), (h) AFM topography and MCC images of pristine NbS2/BN heterostructures. (i), (j) MCC and SP images of water-intercalated heterostructures. (k)-(n) Topography and conductivity images of (k), (l) pristine and (m), (n) water-intercalated NbS2/BN heterostructures using sMIM mode. Scale bars are 1
m. Reproduced from [92]. © IOP Publishing Ltd. All rights reserved. Figure 37. (a) Heater-sample thermal contact resistance (RX) image acquired at TS = 220 K for different areas of interest. (b) Schematic of the heat transport from the tip to the substrate through 2D structures. [200] John Wiley & Sons. [© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim]. (c) Optical and AFM images of a MoS2-WS2 heterostructure. (d) Raman map of the MoS2-WS2 heterostructure device. (e), (f) Temperature rise profiles in this device at different dissipated electrical power at VG = +60 V. The heating predominantly occurs on the WS2-metal vertical junction, and the lateral interface does not contribute to heat localization. The green arrows in (f) show the hot-spot position. [201] John Wiley & Sons. [© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim].
Figure 38. (a) Series of friction images of the MoS2 with increasing normal force. (b) The curves of the friction signals of the sample and substrate vs. normal forces. Data are extracted from (a). Inset is the enlarged view of the dashed rectangle. The 0L, 1L, and 2L represent the substrate, monolayer film, and bilayer film, respectively. (c) Series of in-situ TR images of the MoS2 with increasing normal force, corresponding to (a). (d) Relative dynamic/static thermal resistances vs. normal forces. Data are extracted from (c). Resistance values are the difference values of the sample and substrate. (e) Schematic illustration of static and dynamic TR principle. (f) Thermal resistance image of WS2. The crystallographic orientations of armchair (AC) and zigzag (ZZ) based on the primitive growth edges of WS2 are marked. (g) Polar diagram of the relative dynamic thermal resistance vs. crystallographic orientation of 1L-WS2. The relative dynamic TR values are extracted from SThM images by changing the scan angles. Reproduced from [53] with permission from the Royal Society of Chemistry.
Table 1. Dimensions of typical tips. Reproduced from [16]. © IOP Publishing Ltd. All rights reserved.
Radii of apex (nm) Cone half-angle (O) Length ( m) Silicon tip 7 <10 10-15 Super sharp silicon tip 2 <10 at last 200 nm of tip 10-15 FIB <15 <3 >1.5 EBD 10 4 up to 5 Table 2. Physical properties of some common materials used for AFM cantilevers. Reproduced from [16]. © IOP Publishing Ltd. All rights reserved.
Material property Si (001) [a] Si3N4 GaAs (001) [b] Quartz [c] Diamond Al [d] Polyimide Mechanical Density (g cm-3) 2.329 3-3.3 5.317 2.6 3.5 2.7 1.43[d] Young’s modulus (Gpa) 168.4 for [110] 260-320 [f] 121.5 for [110] 73.1 for [110] 1163.6 for [110] 3.0-3.2[d] 129 for [100] 85.5 for [100] 1050.3 for [100] Torsional modulus G (Gpa) 80 60 31.2 10300 27.8 Poisson ratio 0.27[b] 0.25[f] 0.17[f] 0.1-0.29[f] 0.34 0.41[d] Hardness (load g-1) 1150(25) 680(100) 6360 (long) Speed of sound vs (m s-1) 8430 (long) [b] 9900[c] 5980[d] 17.520[d] 6.360 Thermal Thermal expansion coefficient ( m K-1) 2.92[b] 2.5-3.3[b] 6.86 0.54 1.0 23.03 50-60[b] Heat capacity cP (J kg-1 K-1) 700 45.8 J mol-1 K-1[b] 500 670 518 880 Heat Conductivity (kW-1 mK-1) 156[b] 15-45[b] 45.5 1.46 600-2000 237 0.29-0.35[b] Melting point Tm(K) 1687[b] 1800-1950 [b] 1513 4100[b] 933.47 335-345[b] Optical and electrical Refractive index n at 633 nm 3.4 3.878 1.46 5.7 Static dielectric constant e 11.97[b] 13.18 3.8 5.70[b] 3.4[b] Gap energy (eV) 1.12(ind.) 1.42 9 1017 Electrical resistivity (m) 103 109(undoped) 7 109 Table 3. AFM Techniques and their Applications.
AFM modes Signal of detection Measurement of physical quantity LFM/FFM Friction force Strain domain and strain structure [17] TSM Transverse shear force Crystallographic orientation [18, 19] Dual AC mode Amplitude (A2) and phase (P2) Response of second mode Viscous response detection [20] Multi-harmonic -AFM Higher harmonic components introduced by the nonlinearity of the tip-sample interaction forces Interlayer coupling [7] and local variations of the elastic modulus [7, 20] CR mode Contact resonance frequency and quality factor Contact stiffness and viscous response detection [21] C-AFM Current Local conductivity [22-25] SKPM/KPFM Electric potential Surface potential (SP) [26], work function [27], contact potential difference [28], charge transfer [29, 30], surface point defect/adsorbate [31-33], voltage drop [34], and capacitance coefficients [35], EFM Electrostatic forces Capacitance coefficients [35], SP [36], and dielectric response [37] MH-EFM Electrostatic forces SP [38], work function [39], and mobile charge carriers (MCC) [40] sMIM Microwave reflection Dielectric constant [41, 42], conductivity and permittivity variation [43, 44], charge carrier variations [45], and doping concentration [46] PFM Electromechanical coupling Electromechanical response [47, 48], piezoelectric properties [49], and ferroelectric coercive field [50] MFM Near-field magnetostatic interaction Image flux lines in superconductors, local detection of magnetic interactions to eddy currents, and magnetic dissipation phenomena [51] MRFM Magnetic resonance signals Subsurface defects in solids and dopant distributions in semiconductors [52] SThM Thermal resistance Mechanical-thermal coupling effect [53] NV center combined AFM Magnetic signals, electric signals Magnetic fields [54-57], magnetic textures [58], spin relaxation [59], charge-state control [60], microwave fields imaging [61], living cell temperature imaging [62] AFM-IR Thermal expansion IR absorption spectra of nanoscale regions, sample temperature increase, distribution of chemical species [63] SNOM Near field optical signal Distribution of the electromagnetic radiation [64] Nano-FTIR Near field optical signal Molecular vibrational spectra, infrared absorption spectrum of organic samples [65] Table 4. Comparison of young’s moduli and breaking strengths for several engineering materials. Reprinted with permission from [175]. Copyright (2011) American Chemical Society.
Material Young’s modulus EYoung (Gpa) Breaking strength maxeff (Gpa) Breaking strength/Young’s modulus (%) Stainless steel ASTM-A514 205 0.9 0.4 Molybdenum 329 0.5-1.2 0.15-0.36 Polyimide 2.5 0.231 9 PDMS 0.3-0.87 2.24 2.5 Kevlar 49 112 3 2.6 Monolayer MoS2 270 16-30 6-11 Bulk MoS2 238 WS2 nanotubes 152 3.7-16.3 2.4-10 Carbon nanotubes 1000 11-63 1.1-63 Graphene 1000 130 13 -
[1] Voigtlander B 2019 Atomic Force MicroscopyBerlinSpringer doi: 10.1007/978-3-030-13654-3 [2] Bhushan B 2010 Handbook of NanotechnologyBerlinSpringer doi: 10.1007/978-3-642-02525-9 [3] Binnig G, Rohrer H, Gerber C, Weibel E 1982 Surface studies by scanning tunneling microscopy Phys. Rev. Lett. 49 57-61 doi: 10.1103/PhysRevLett.49.57 [4] Binnig G, Rohrer H, Gerbe C, Weibel E 1983 7 7 reconstruction on Si (111) resolved in real space Phys. Rev. Lett. 50 120-3 doi: 10.1103/PhysRevLett.50.120 [5] Belianinov A, Kalinin S V, Jesse S 2015 Complete information acquisition in dynamic force microscopy Nat. Commun. 6 6550 doi: 10.1038/ncomms7550 [6] Jang S K, Youn J, Song Y J, Lee S 2016 Synthesis and characterization of hexagonal boron nitride as a gate dielectric Sci. Rep. 6 30449 doi: 10.1038/srep30449 [7] Zheng Z, Xu R, Ye S, Hussain S, Ji W, Cheng P, Li Y, Sugawara Y, Cheng Z 2017 High harmonic exploring on different materials in dynamic atomic force microscopy Sci. China Technol. Sci. 61 446-52 doi: 10.1007/s11431-017-9161-4 [8] Benstetter G, Biberger R, Liu D P 2009 A review of advanced scanning probe microscope analysis of functional films and semiconductor devices Thin Solid Films 517 5100-5 doi: 10.1016/j.tsf.2009.03.176 [9] Horcas I, Fernandez R, Gomez-Rodriguez J M, Colchero J, Gomez-Herrero J, Baro A M 2007 WSXM: a software for scanning probe microscopy and a tool for nanotechnology Rev. Sci. Instrum. 78 013705 doi: 10.1063/1.2432410 [10] Binnig G, Quate C F, Gerber C 1986 Atomic force microscope Phys. Rev. Lett. 56 930 doi: 10.1103/PhysRevLett.56.930 [11] Albrecht T R, Grtter P, Horne D, Rugar D 1991 Frequency modulation detection using highQ cantilevers for enhanced force microscope sensitivity J. Appl. Phys. 69 668-73 doi: 10.1063/1.347347 [12] Bettac A, Koeble J, Winkler K, Uder B, Maier M, Feltz A 2009 QPlus: atomic force microscopy on single-crystal insulators with small oscillation amplitudes at 5 K Nanotechnology 20 264009 doi: 10.1088/0957-4484/20/26/264009 [13] Groning O, et al 2018 Engineering of robust topological quantum phases in graphene nanoribbons Nature 560 209-13 doi: 10.1038/s41586-018-0375-9 [14] Ruffieux P, et al 2016 On-surface synthesis of graphene nanoribbons with zigzag edge topology Nature 531 489-93 doi: 10.1038/nature17151 [15] Zhang J, Chen P, Yuan B, Ji W, Cheng Z, Qiu X 2013 Real-space identification of intermolecular bonding with atomic force microscopy Science 342 611-4 doi: 10.1126/science.1242603 [16] Yacoot A, Koenders L 2008 Aspects of scanning force microscope probes and their effects on dimensional measurement J. Phys. D: Appl. Phys. 41 103001 doi: 10.1088/0022-3727/41/10/103001 [17] Hussain S, et al 2020 Strain-induced hierarchical ripples in MoS2 layers investigated by atomic force microscopy Appl. Phys. Lett. 117 153102 doi: 10.1063/5.0023405 [18] Xu K, et al 2019 Shear anisotropy-driven crystallographic orientation imaging in flexible hexagonal two-dimensional atomic crystals Appl. Phys. Lett. 115 063101 doi: 10.1063/1.5096418 [19] Hussain S, et al 2021 Toplayer-dependent crystallographic orientation imaging in the bilayer two-dimensional materials with transverse shear microscopy Front. Phys. 16 53504 doi: 10.1007/s11467-021-1072-y [20] Garcia R, Herruzo E T 2012 The emergence of multifrequency force microscopy Nat. Nanotechnol. 7 217-26 doi: 10.1038/nnano.2012.38 [21] Yablon D G 2013 Scanning Probe Microscopy in Industrial ApplicationsNew York: Wiley [22] Shaw J E, Perumal A, Bradley D D C, Stavrinou P N, Anthopoulos T D 2016 Nanoscale current spreading analysis in solution-processed graphene oxide/silver nanowire transparent electrodes via conductive atomic force microscopy J. Appl. Phys. 119 195501 doi: 10.1063/1.4949502 [23] Houz F, Meyer R, Schneegans O, Boyer L 1996 Imaging the local electrical properties of metal surfaces by atomic force microscopy with conducting probes Appl. Phys. Lett. 69 1975-7 doi: 10.1063/1.117179 [24] Yang J, Gordiichuk P, Zheliuk O, Lu J, Herrmann A, Ye J 2017 Role of defects in tuning the electronic properties of monolayer WS2 grown by chemical vapor deposition Phys. Status Solidi 11 1700302 doi: 10.1002/pssr.201700302 [25] Zhang L, Mitani Y 2006 Structural and electrical evolution of gate dielectric breakdown observed by conductive atomic force microscopy Appl. Phys. Lett. 88 032906 doi: 10.1063/1.2166679 [26] Mi S, Guo J, Wang H, Xia T, Cheng Z 2022 Scanning kelvin probe microcopy study of magnetic topological insulators MnBi2Te4(Bi2Te3n Chin. J. Vac. Sci. Technol. 42 585-92 doi: 10. 13922 / j. cnki. cjvst.202205015 [27] Filleter T, Emtsev K V, Seyller T, Bennewitz R 2008 Local work function measurements of epitaxial graphene Appl. Phys. Lett. 93 133117 doi: 10.1063/1.2993341 [28] Wen H F, Li Y J, Arima E, Naitoh Y, Sugawara Y, Xu R, Cheng Z H 2017 Investigation of tunneling current and local contact potential difference on the TiO2(110) surface by AFM/KPFM at 78K Nanotechnology 28 105704 doi: 10.1088/1361-6528/aa5aef [29] Shen Y, Zhang X Q, Wang Y, Zhou X J, Hu J, Guo S W, Zhang Y 2013 Charge transfer between reduced graphene oxide sheets on insulating substrates Appl. Phys. Lett. 103 053107 doi: 10.1063/1.4817252 [30] Xu R, et al 2018 Nanoscale charge transfer and diffusion at the MoS2/SiO2 interface by atomic force microscopy: contact injection versus triboelectrification Nanotechnology 29 355701 doi: 10.1088/1361-6528/aacad7 [31] Wen H F, Adachi Y, Zhang Q Z, Miyazaki M, Sugawara Y, Li Y J 2019 Identification of atomic defects and adsorbate on rutile TiO2(110)-(11) surface by atomic force microscopy J. Phys. Chem. C 123 25756-60 doi: 10.1021/acs.jpcc.9b07949 [32] Wen H F, Sugawara Y, Li Y J 2020 Multi-channel exploration of O adatom on TiO2(110) surface by scanning probe microscopy Nanomaterials 10 1506 doi: 10.3390/nano10081506 [33] Wen H F, Sugawara Y, Li Y J 2021 Exploring the nature of hydrogen of rutile TiO2(110) at 78 K Surf. Interfaces 26 101339 doi: 10.1016/j.surfin.2021.101339 [34] Yan L, Punckt C, Aksay I A, Mertin W, Bacher G 2011 Local voltage drop in a single functionalized graphene sheet characterized by Kelvin probe force microscopy Nano Lett. 11 3543-9 doi: 10.1021/nl201070c [35] Lucchesi M, Privitera G, Labardi M, Prevosto D, Capaccioli S, Pingue P 2009 Electrostatic force microscopy and potentiometry of realistic nanostructured systems J. Appl. Phys. 105 054301 doi: 10.1063/1.3082125 [36] Datta S S, Strachan D R, Mele E J, Johnson A T C 2009 Surface potentials and layer charge distributions in few-layer graphene films Nano Lett. 9 7-11 doi: 10.1021/nl8009044 [37] Oliveira C K, Matos M J S, Mazzoni M S C, Chacham H, Neves B R A 2012 Anomalous response of supported few-layer hexagonal boron nitride to DC electric fields: a confined water effect? Nanotechnology 23 175703 doi: 10.1088/0957-4484/23/17/175703 [38] Collins L, Kilpatrick J I, Weber S A L, Tselev A, Vlassiouk I V, Ivanov I N, Jesse S, Kalinin S V, Rodriguez B J 2013 Open loop Kelvin probe force microscopy with single and multi-frequency excitation Nanotechnology 24 475702 doi: 10.1088/0957-4484/24/47/475702 [39] Li C, Ding X D, Lin G C 2013 Study on multi-frequency method for electrostatic force microscopy in air Integr. Ferroelectr. 145 59-67 doi: 10.1080/10584587.2013.788385 [40] Jiang Y, Qi Q, Wang R, Zhang J, Xue Q K, Wang C, Jiang C, Qiu X H 2011 Direct observation and measurement of mobile charge carriers in a monolayer organic semiconductor on a dielectric substrate ACS Nano 5 6195-201 doi: 10.1021/nn200760r [41] Wu D, et al 2015 Thickness-dependent dielectric constant of few-layer In2Se3 nanoflakes Nano Lett. 15 8136-40 doi: 10.1021/acs.nanolett.5b03575 [42] Feng Y, et al 2015 Synthesis of large-area highly crystalline monolayer molybdenum disulfide with tunable grain size in a H2 atmosphere ACS Appl. Mater. Interfaces 7 22587 doi: 10.1021/acsami.5b07038 [43] Liu Y, et al 2015 Thermal oxidation of WSe2 nanosheets adhered on SiO2/Si substrates Nano Lett. 15 4979-84 doi: 10.1021/acs.nanolett.5b02069 [44] Kundhikanjana W, Lai K, Wang H, Dai H, Kelly M A, Shen Z-X 2009 Hierarchy of electronic properties of chemically derived and pristine graphene probed by microwave imaging Nano Lett. 9 3762-5 doi: 10.1021/nl901949z [45] Berweger S, Blanchard P T, Brubaker M D, Coakley K J, Sanford N A, Wallis T M, Bertness K A, Kabos P 2016 Near-field control and imaging of free charge carrier variations in GaN nanowires Appl. Phys. Lett. 108 073101 doi: 10.1063/1.4942107 [46] Brinciotti E, et al 2015 Probing resistivity and doping concentration of semiconductors at the nanoscale using scanning microwave microscopy Nanoscale 7 14715-22 doi: 10.1039/C5NR04264J [47] Lu A-Y, et al 2017 Janus monolayers of transition metal dichalcogenides Nat. Nanotechnol. 12 744-9 doi: 10.1038/nnano.2017.100 [48] Kim S K, Bhatia R, Kim T-H, Seol D, Kim J H, Kim H, Seung W, Kim Y, Lee Y H, Kim S-W 2016 Directional dependent piezoelectric effect in CVD grown monolayer MoS2 for flexible piezoelectric nanogenerators Nano Energy 22 483-9 doi: 10.1016/j.nanoen.2016.02.046 [49] Park M, Hong S, Kim J, Hong J, No K 2011 Nanoscale ferroelectric switching behavior at charged domain boundaries studied by angle-resolved piezoresponse force microscopy Appl. Phys. Lett. 99 142909 doi: 10.1063/1.3646761 [50] Kim S, Gopalan V, Gruverman A 2002 Coercive fields in ferroelectrics: a case study in lithium niobate and lithium tantalate Appl. Phys. Lett. 80 2740-2 doi: 10.1063/1.1470247 [51] Hartmann U 1999 Magnetic force microscopy Annu. Rev. Mater. Sci. 29 53-87 doi: 10.1146/annurev.matsci.29.1.53 [52] Sidles J A, Garbini J L, Bruland K J, Rugar D, Zger O, Hoen S, Yannoni C S 1995 Magnetic resonance force microscopy Rev. Mod. Phys. 67 249-65 doi: 10.1103/RevModPhys.67.249 [53] Xu K, Ye S, Lei L, Meng L, Hussain S, Zheng Z, Zeng H, Ji W, Xu R, Cheng Z 2018 Dynamic interfacial mechanical-thermal characteristics of atomically thin two-dimensional crystals Nanoscale 10 13548-54 doi: 10.1039/C8NR03586E [54] Maletinsky P, Hong S, Grinolds M, Hausmann B, Lukin M D, Walsworth R L, Loncar M, Yacoby A 2012 A robust scanning diamond sensor for nanoscale imaging with single nitrogen-vacancy centres Nat. Nanotechnol. 7 320-4 doi: 10.1038/nnano.2012.50 [55] Tetienne J-P, Rondin L, Spinicelli P, Chipaux M, Debuisschert T, Roch J-F, Jacques V 2012 Magnetic-field-dependent photodynamics of single NV defects in diamond: an application to qualitative all-optical magnetic imaging New J. Phys. 14 103033 doi: 10.1088/1367-2630/14/10/103033 [56] Huxter W S, Palm M L, Davis M L, Welter P, Lambert C-H, Trassin M, Degen C L 2022 Scanning gradiometry with a single spin quantum magnetometer Nat. Commun. 13 3761 doi: 10.1038/s41467-022-31454-6 [57] Grinolds M S, Hong S, Maletinsky P, Luan L, Lukin M D, Walsworth R L, Yacoby A 2013 Nanoscale magnetic imaging of a single electron spin under ambient conditions Nat. Phys. 9 215-9 doi: 10.1038/nphys2543 [58] Song T, et al 2021 Direct visualization of magnetic domains and moir magnetism in twisted 2D magnets Science 374 1140-4 doi: 10.1126/science.abj7478 [59] Ariyaratne A, Bluvstein D, Myers B A, Jayich A C B 2018 Nanoscale electrical conductivity imaging using a nitrogen-vacancy center in diamond Nat. Commun. 9 2406 doi: 10.1038/s41467-018-04798-1 [60] Bian K, Zheng W, Zeng X, Chen X, Stohr R, Denisenko A, Yang S, Wrachtrup J, Jiang Y 2021 Nanoscale electric-field imaging based on a quantum sensor and its charge-state control under ambient condition Nat. Commun. 12 2457 doi: 10.1038/s41467-021-22709-9 [61] Appel P, Ganzhorn M, Neu E, Maletinsky P 2015 Nanoscale microwave imaging with a single electron spin in diamond New J. Phys. 17 112001 doi: 10.1088/1367-2630/17/11/112001 [62] Kucsko G, Maurer P C, Yao N Y, Kubo M, Noh H J, Lo P K, Park H, Lukin M D 2013 Nanometre-scale thermometry in a living cell Nature 500 54-58 doi: 10.1038/nature12373 [63] Dazzi A, Prater C B 2017 AFM-IR: technology and applications in nanoscale infrared spectroscopy and chemical imaging Chem. Rev. 117 5146-73 doi: 10.1021/acs.chemrev.6b00448 [64] Bazylewski P, Ezugwu S, Fanchini G 2017 A review of three-dimensional scanning near-field optical microscopy (3D-SNOM) and its applications in nanoscale light management Appl. Sci. 7 973 doi: 10.3390/app7100973 [65] Huth F, Govyadinov A, Amarie S, Nuansing W, Keilmann F, Hillenbrand R 2012 Nano-FTIR absorption spectroscopy of molecular fingerprints at 20 nm spatial resolution Nano Lett. 12 3973 doi: 10.1021/nl301159v [66] Choi J S, et al 2011 Friction anisotropy-driven domain imaging on exfoliated monolayer graphene Science 333 607-10 doi: 10.1126/science.1207110 [67] McNeill C 2011 Imaging the domain structure of organic semiconductor films J. Polym. Sci. 49 909-19 doi: 10.1002/polb.22270 [68] Kalihari V, Tadmor E B, Haugstad G, Frisbie C D 2008 Grain orientation mapping of polycrystalline organic semiconductor films by transverse shear microscopy Adv. Mater. 20 4033 doi: 10.1002/adma.200801834 [69] Martinez-Martin D, Herruzo E T, Dietz C, Gomez-Herrero J, Garcia R 2011 Noninvasive protein structural flexibility mapping by bimodal dynamic force microscopy Phys. Rev. Lett. 106 198101 doi: 10.1103/PhysRevLett.106.198101 [70] Vasudevan R K, Okatan M B, Rajapaksa I, Kim Y, Marincel D, Trolier-mckinstry S, Jesse S, Valanoor N, Kalinin S V 2013 Higher order harmonic detection for exploring nonlinear interactions with nanoscale resolution Sci. Rep. 3 2677 doi: 10.1038/srep02677 [71] Tetard L, Passian A, Thundat T 2010 New modes for subsurface atomic force microscopy through nanomechanical coupling Nat. Nanotechnol. 5 105 doi: 10.1038/nnano.2009.454 [72] Cheng Z, Zheng Z, Xu R 2016 Multi-frequency atomic force microscopy Sci. Sin. Technol. 46 437-50 doi: 10.1360/N092015-00246 [73] Zheng Z-Y, Xu R, Xu K-Q, Ye S-L, Pang F, Lei L, Hussain S, Liu X-M, Ji W, Cheng Z-H 2019 Real-space visualization of intercalated water phases at the hydrophobic graphene interface with atomic force microscopy Front. Phys. 15 23601 doi: 10.1007/s11467-019-0933-0 [74] Nievergelt A P, Adams J D, Odermatt P D, Fantner G E 2014 High-frequency multimodal atomic force microscopy Beilstein J. Nanotechnol. 5 2459 doi: 10.3762/bjnano.5.255 [75] Dietz C, Schulze M, Voss A, Riesch C, Stark R W 2015 Bimodal frequency-modulated atomic force microscopy with small cantilevers Nanoscale 7 1849-56 doi: 10.1039/C4NR05907G [76] Zheng Z-Y, et al 2020 Local probe of the interlayer coupling strength of few-layers SnSe by contact-resonance atomic force microscopy Front. Phys. 15 63505 doi: 10.1007/s11467-020-0994-0 [77] Rabe U, Arnold W 1994 Acoustic microscopy by atomic force microscopy Appl. Phys. Lett. 64 1493-5 doi: 10.1063/1.111869 [78] Yamanaka K, Nakano S 1996 Ultrasonic atomic force microscope with overtone excitation of cantilever Jpn. J. Appl. Phys. 35 3787-92 doi: 10.1143/JJAP.35.3787 [79] Yamanaka K, Kobari K, Tsuji T 2008 Evaluation of functional materials and devices using atomic force microscopy with ultrasonic measurements Jpn. J. Appl. Phys. 47 6070-6 doi: 10.1143/JJAP.47.6070 [80] Li Q, Jesse S, Tselev A, Collins L, Yu P, Kravchenko I, Kalinin S V, Balke N 2015 Probing local bias-induced transitions using photothermal excitation contact resonance atomic force microscopy and voltage spectroscopy ACS Nano 9 1848-57 doi: 10.1021/nn506753u [81] Yablon D G, Gannepalli A, Proksch R, Killgore J, Hurley D C, Grabowski J, Tsou A H 2012 Quantitative viscoelastic mapping of polyolefin blends with contact resonance atomic force microscopy Macromolecules 45 4363-70 doi: 10.1021/ma2028038 [82] Gannepalli A, Yablon D G, Tsou A H, Proksch R 2011 Mapping nanoscale elasticity and dissipation using dual frequency contact resonance AFM Nanotechnology 22 355705 doi: 10.1088/0957-4484/22/35/355705 [83] Nonnenmacher M, Oboyle M P, Wickramasinghe H K 1991 Kelvin probe force microscopy Appl. Phys. Lett. 58 2921-3 doi: 10.1063/1.105227 [84] Jacobs H O, Leuchtmann P, Homan O J, Stemmer A 1998 Resolution and contrast in Kelvin probe force microscopy J. Appl. Phys. 84 1168-73 doi: 10.1063/1.368181 [85] Hsu J W P, Ng H M, Sergent A M, Chu S N G 2002 Scanning Kelvin force microscopy imaging of surface potential variations near threading dislocations in GaN Appl. Phys. Lett. 81 3579-81 doi: 10.1063/1.1519732 [86] Ren J, Liess H-D, Mackel R, Baumgartner H 1995 Scanning Kelvin microscope: a new method for surface investigations Fresenius J. Anal. Chem. 353 303-6 doi: 10.1007/BF00322056 [87] Collins L, Jesse S, Balke N, Rodriguez B J, Kalinin S, Li Q 2015 Band excitation Kelvin probe force microscopy utilizing photothermal excitation Appl. Phys. Lett. 106 104102 doi: 10.1063/1.4913910 [88] Guo S L, Kalinin S V, Jesse S 2012 Open-loop band excitation Kelvin probe force microscopy Nanotechnology 23 125704 doi: 10.1088/0957-4484/23/12/125704 [89] Melitz W, Shen J, Kummel A C, Lee S 2011 Kelvin probe force microscopy and its application Surf. Sci. Rep. 66 1-27 doi: 10.1016/j.surfrep.2010.10.001 [90] Strelcov E, Arble C, Guo H X, Hoskins B D, Yulaev A, Vlassiouk I V, Zhitenev N B, Tselev A, Kolmakov A 2020 Nanoscale mapping of the double layer potential at the graphene- electrolyte interface Nano Lett. 20 1336-44 doi: 10.1021/acs.nanolett.9b04823 [91] Hussain S, Xu K, Ye S, Lei L, Liu X, Xu R, Xie L, Cheng Z H 2019 Local electrical characterization of two-dimensional materials with functional atomic force microscopy Front. Phys. 14 33401 doi: 10.1007/s11467-018-0879-7 [92] Xu R, et al 2019 Interfacial water intercalation-induced metal-insulator transition in NbS2/BN heterostructure Nanotechnology 30 205702 doi: 10.1088/1361-6528/ab0452 [93] De Wolf P, Stephenson R, Trenkler T, Clarysse T, Hantschel T, Vandervorst W 2000 Status and review of two-dimensional carrier and dopant profiling using scanning probe microscopy J. Vac. Sci. Technol. B 18 361-8 doi: 10.1116/1.591198 [94] Girard P 2001 Electrostatic force microscopy: principles and some applications to semiconductors Nanotechnology 12 485-90 doi: 10.1088/0957-4484/12/4/321 [95] Zhang K, Marzari N, Zhang Q 2013 Covalently functionalized metallic single-walled carbon nanotubes studied using electrostatic force microscopy and dielectric force microscopy J. Phys. Chem. C 117 24570-8 doi: 10.1021/jp4076178 [96] Kimura K, Kobayashi K, Yamada H, Matsushige K 2003 Two-dimensional dopant profiling by scanning capacitance force microscopy Appl. Surf. Sci. 210 93-98 doi: 10.1016/S0169-4332(02)01486-1 [97] Kobayashi K, Yamada H, Matsushige K 2004 Method and apparatus for measuring values of physical property US Patent 6823724B1 [98] Ding X D, An J, Xu J B, Li C, Zeng R Y 2009 Improving lateral resolution of electrostatic force microscopy by multifrequency method under ambient conditions Appl. Phys. Lett. 94 223109 doi: 10.1063/1.3147198 [99] Fumagalli L, Esteban-Ferrer D, Cuervo A, Carrascosa J L, Gomila G 2012 Label-free identification of single dielectric nanoparticles and viruses with ultraweak polarization forces Nat. Mater. 11 808-16 doi: 10.1038/nmat3369 [100] Li N, Shang Y, Xu R, Jiang Q, Liu J, Wang L, Cheng Z, Ding B 2019 Precise organization of metal and metal oxide nanoclusters into arbitrary patterns on DNA origami J. Am. Chem. Soc. 141 17968-72 doi: 10.1021/jacs.9b09308 [101] Collins L, Kilpatrick J I, Vlassiouk I V, Tselev A, Weber S A L, Jesse S, Kalinin S V, Rodriguez B J 2014 Dual harmonic Kelvin probe force microscopy at the graphene-liquid interface Appl. Phys. Lett. 104 133103 doi: 10.1063/1.4870074 [102] Martin Y, Abraham D W, Wickramasinghe H K 1988 High-resolution capacitance measurement and potentiometry by force microscopy Appl. Phys. Lett. 52 1103-5 doi: 10.1063/1.99224 [103] Lai K, Ji M B, Leindecker N, Kelly M A, Shen Z X 2007 Atomic-force-microscope-compatible near-field scanning microwave microscope with separated excitation and sensing probes Rev. Sci. Instrum. 78 063702 doi: 10.1063/1.2746768 [104] Lai K, Kundhikanjana W, Kelly M, Shen Z X 2008 Modeling and characterization of a cantilever-based near-field scanning microwave impedance microscope Rev. Sci. Instrum. 79 063703 doi: 10.1063/1.2949109 [105] Yang Y, Lai K, Tang Q, Kundhikanjana W, Kelly M A, Zhang K, Shen Z-X, Li X 2012 Batch-fabricated cantilever probes with electrical shielding for nanoscale dielectric and conductivity imaging J. Micromech. Microeng. 22 115040 doi: 10.1088/0960-1317/22/11/115040 [106] Lai K, Kundhikanjana W, Kelly M A, Shen Z X 2008 Calibration of shielded microwave probes using bulk dielectrics Appl. Phys. Lett. 93 123105 doi: 10.1063/1.2990638 [107] Seabron E, MacLaren S, Xie X, Rotkin S V, Rogers J A, Wilson W L 2016 Scanning probe microwave reflectivity of aligned single-walled carbon nanotubes: imaging of electronic structure and quantum behavior at the nanoscale ACS Nano 10 360-8 doi: 10.1021/acsnano.5b04975 [108] Lai K, Peng H, Kundhikanjana W, Schoen D T, Xie C, Meister S, Cui Y, Kelly M A, Shen Z-X 2009 Nanoscale electronic inhomogeneity in In2Se3 nanoribbons revealed by microwave impedance microscopy Nano Lett. 9 1265-9 doi: 10.1021/nl900222j [109] Lai K, Nakamura M, Kundhikanjana W, Kawasaki M, Tokura Y, Kelly M A, Shen Z-X 2010 Mesoscopic percolating resistance network in a strained manganite thin film Science 329 190-3 doi: 10.1126/science.1189925 [110] Kundhikanjana W, Lai K, Kelly M A, Shen Z-X 2011 Cryogenic microwave imaging of metal-insulator transition in doped silicon Rev. Sci. Instrum. 82 033705 doi: 10.1063/1.3554438 [111] Lai K, Kundhikanjana W, Kelly M A, Shen Z-X, Shabani J, Shayegan M 2011 Imaging of coulomb-driven quantum Hall edge states Phys. Rev. Lett. 107 176809 doi: 10.1103/PhysRevLett.107.176809 [112] Ma E Y, Bryant B, Tokunaga Y, Aeppli G, Tokura Y, Shen Z-X 2015 Charge-order domain walls with enhanced conductivity in a layered manganite Nat. Commun. 6 7595 doi: 10.1038/ncomms8595 [113] Ma E Y, Cui Y-T, Ueda K, Tang S, Chen K, Tamura N, Wu P M, Fujioka J, Tokura Y, Shen Z-X 2015 Mobile metallic domain walls in an all-in-all-out magnetic insulator Science 350 538 doi: 10.1126/science.aac8289 [114] Ponath P, et al 2015 Carrier density modulation in a germanium heterostructure by ferroelectric switching Nat. Commun. 6 6067 doi: 10.1038/ncomms7067 [115] Lei L, et al 2018 Local characterization of mobile charge carriers by two electrical AFM modes: multi-harmonic EFM vs. sMIM J. Phys. Commun. 2 025013 doi: 10.1088/2399-6528/aaa85f [116] Tsai Y, et al 2017 Tailoring semiconductor lateral multijunctions for giant photoconductivity enhancement Adv. Mater. 29 1703680 doi: 10.1002/adma.201703680 [117] Wu D, et al 2016 Uncovering edge states and electrical inhomogeneity in MoS2 field-effect transistors Proc. Natl Acad. Sci. USA 113 8583-8 doi: 10.1073/pnas.1605982113 [118] Xu R, Zheng Z Y, Ji W, Cheng Z H 2015 Advance scanning mcrowave microscopy Prog. Phys. 35 241-56 doi: 10.13725/j.cnki.pip.2015.06.001 [119] Barber M E, Ma E Y, Shen Z-X 2022 Microwave impedance microscopy and its application to quantum materials Nat. Rev. Phys. 4 61-74 doi: 10.1038/s42254-021-00386-3 [120] Williams C C, Wickramasinghe H K 1986 Scanning thermal profiler Appl. Phys. Lett. 49 1587-9 doi: 10.1063/1.97288 [121] Majumdar A 1999 Scanning thermal microscopy Annu. Rev. Mater. Res. 29 505-85 doi: 10.1146/annurev.matsci.29.1.505 [122] Lai J, Chandrachood M, Majumdar A, Carrejo J P 1995 Thermal detection of device failure by atomic-force microscopy IEEE Electron Device Lett. 16 312-5 doi: 10.1109/55.388718 [123] Fiege G B M, Feige V, Phang J C H, Maywald M, Gorlich S, Balk L J 1998 Failure analysis of integrated devices by scanning thermal microscopy (SThM) Microelectron. Reliab. 38 957-61 doi: 10.1016/S0026-2714(98)00086-9 [124] Kwon O, Majumdar A 2003 Cross-sectional thermal imaging of a metal-oxide-semiconductor field-effect ttransistor Microscale Thermophys. Eng. 7 349-54 doi: 10.1080/10893950390243617 [125] Boroumand F A, Voigt M, Lidzey D G, Hammiche A, Hill G 2004 Imaging Joule heating in a conjugated-polymer light-emitting diode using a scanning thermal microscope Appl. Phys. Lett. 84 4890-2 doi: 10.1063/1.1762988 [126] Luo K, Herrick R W, Majumdar A, Petroff P 1997 Scanning thermal microscopy of a vertical-cavity surface-emitting laser Appl. Phys. Lett. 71 1604-6 doi: 10.1063/1.119991 [127] Shi L, Plyasunov S, Bachtold A, McEuen P L, Majumdar A 2000 Scanning thermal microscopy of carbon nanotubes using batch-fabricated probes Appl. Phys. Lett. 77 4295-7 doi: 10.1063/1.1334658 [128] Shi L, Zhou J, Kim P, Bachtold A, Majumdar A, McEuen P L 2009 Thermal probing of energy dissipation in current-carrying carbon nanotubes J. Appl. Phys. 105 104306 doi: 10.1063/1.3126708 [129] Goms S, Assy A, Chapuis P-O 2015 Scanning thermal microscopy: a review Phys. Status Solidi a 212 477-94 doi: 10.1002/pssa.201400360 [130] Majumdar A, Lai J, Chandrachood M, Nakabeppu O, Wu Y, Shi Z 1995 Thermal imaging by atomic-force microscopy using thermocouple cantilever probes Rev. Sci. Instrum. 66 3584-92 doi: 10.1063/1.1145474 [131] Suzuki Y 1996 Novel microcantilever for scanning thermal imaging microscopy Jpn. J. Appl. Phys. 35 L352-4 doi: 10.1143/JJAP.35.L352 [132] Luo K, Shi Z, Lai J, Majumdar A 1996 Nanofabrication of sensors on cantilever probe tips for scanning multiprobe microscopy Appl. Phys. Lett. 68 325-7 doi: 10.1063/1.116074 [133] Rangelow I W, Gotszalk T, Abedinov N, Grabiec P, Edinger K 2001 Thermal nano-probe Microelectron. Eng. 57-58 737-48 doi: 10.1016/S0167-9317(01)00466-X [134] Pylkki R J, Moyer P J, West P E 1994 Scanning near-field optical microscopy and scanning thermal microscopy Jpn. J. Appl. Phys. 33 3785-90 doi: 10.1143/JJAP.33.3785 [135] Edinger K, Gotszalk T, Rangelow I W 2001 Novel high resolution scanning thermal probe J. Vac. Sci. Technol. B 19 2856-60 doi: 10.1116/1.1420580 [136] Zhang Y, Dobson P S, Weaver J M R 2011 Batch fabricated dual cantilever resistive probe for scanning thermal microscopy Microelectron. Eng. 88 2435-8 doi: 10.1016/j.mee.2011.02.040 [137] Aigouy L, Tessier G, Mortier M, Charlot B 2005 Scanning thermal imaging of microelectronic circuits with a fluorescent nanoprobe Appl. Phys. Lett. 87 184105 doi: 10.1063/1.2123384 [138] Aigouy L, Saidi E, Lalouat L C, Labguerie-Ega J, Mortier M, Low P, Bergaud C 2009 AC thermal imaging of a microwire with a fluorescent nanocrystal: influence of the near field on the thermal contrast J. Appl. Phys. 106 074301 doi: 10.1063/1.3233940 [139] Nakabeppu O, Chandrachood M, Wu Y, Lai J, Majumdar A 1995 Scanning thermal imaging microscopy using composite cantilever probes Appl. Phys. Lett. 66 694-6 doi: 10.1063/1.114102 [140] Chung J, Kim K, Hwang G, Kwon O, Choi Y K, Lee J S 2012 Quantitative temperature profiling through null-point scanning thermal microscopy Int. J. Therm. Sci. 62 109-13 doi: 10.1016/j.ijthermalsci.2011.11.012 [141] Chung J, Kim K, Hwang G, Kwon O, Jung S, Lee J, Lee J W, Kim G T 2010 Quantitative temperature measurement of an electrically heated carbon nanotube using the null-point method Rev. Sci. Instrum. 81 114901 doi: 10.1063/1.3499504 [142] Hwang G, Chung J, Kwon O 2014 Enabling low-noise null-point scanning thermal microscopy by the optimization of scanning thermal microscope probe through a rigorous theory of quantitative measurement Rev. Sci. Instrum. 85 114901 doi: 10.1063/1.4901094 [143] Kim K, Chung J, Hwang G, Kwon O, Lee J S 2011 Quantitative measurement with scanning thermal microscope by preventing the distortion due to the heat transfer through the air ACS Nano 5 8700-9 doi: 10.1021/nn2026325 [144] Yoon K, Hwang G, Chung J, Kim H G, Kwon O, Kihm K D, Lee J S 2014 Measuring the thermal conductivity of residue-free suspended graphene bridge using null point scanning thermal microscopy Carbon 76 77-83 doi: 10.1016/j.carbon.2014.04.051 [145] Gotsmann B, Lantz M A 2013 Quantized thermal transport across contacts of rough surfaces Nat. Mater. 12 59-65 doi: 10.1038/nmat3460 [146] Kim K, Jeong W, Lee W, Reddy P 2012 Ultra-high vacuum scanning thermal microscopy for nanometer resolution quantitative thermometry ACS Nano 6 4248-57 doi: 10.1021/nn300774n [147] Novoselov K, Geim A, Morozov S, Jiang D, Zhang Y, Dubonos S, Grigorieva I, Firsov A 2004 Electric field effect in atomically thin carbon films Science 306 666-9 doi: 10.1126/science.1102896 [148] Novoselov K S, Mishchenko A, Carvalho A, Castro Neto A H 2016 2D materials and van der Waals heterostructures Science 353 9439 doi: 10.1126/science.aac9439 [149] Wang Q H, Kalantar-Zadeh K, Kis A, Coleman J N, Strano M S 2012 Electronics and optoelectronics of two-dimensional transition metal dichalcogenides Nat. Nanotechnol. 7 699-712 doi: 10.1038/nnano.2012.193 [150] Liu L, Kumar S B, Ouyang Y, Guo J 2011 Performance limits of monolayer transition metal dichalcogenide transistors IEEE Trans. Electron Devices 58 3042-7 doi: 10.1109/TED.2011.2159221 [151] Xu R, et al 2020 Atomically asymmetric inversion scales up to mesoscopic single-crystal monolayer flakes ACS Nano 14 13834-40 doi: 10.1021/acsnano.0c06198 [152] Dai Z, et al 2019 Mechanical responses of boron-doped monolayer graphene Carbon 147 594-601 doi: 10.1016/j.carbon.2019.03.014 [153] Lei L, et al 2021 Size-dependent strain-engineered nanostructures in MoS2 monolayer investigated by atomic force microscopy Nanotechnology 32 465703 doi: 10.1088/1361-6528/ac1b54 [154] Xu R, et al 2022 Visualization of strain-engineered nanopattern in center-confined mesoscopic WS2 monolayer flakes J. Phys. Chem. C 126 7184-92 doi: 10.1021/acs.jpcc.1c10538 [155] Ahn G H, Amani M, Rasool H, Lien D-H, Mastandrea J P, Ager Iii J W, Dubey M, Chrzan D C, Minor A M, Jave A 2017 Strain-engineered growth of two-dimensional materials Nat. Commun. 8 608 doi: 10.1038/s41467-017-00516-5 [156] Pang F, et al 2021 Strain-engineered rippling and manipulation of single layer WS2 by atomic force microscopy J. Phys. Chem. C 125 8696-703 doi: 10.1021/acs.jpcc.1c01179 [157] Peimyoo N, Shang J Z, Cong C X, Shen X N, Wu X Y, Yeow E K L, Yu T 2013 Nonblinking, intense two-dimensional light emitter: monolayer WS2 triangles ACS Nano 7 10985-94 doi: 10.1021/nn4046002 [158] Kim M S, Yun S J, Lee Y, Seo C, Han G H, Kim K K, Lee Y H, Kim J 2016 Biexciton emission from edges and grain boundaries of triangular WS2 monolayers ACS Nano 10 2399-405 doi: 10.1021/acsnano.5b07214 [159] Gutierrez H R, Perea-Lopez N, Elias A L, Berkdemir A, Wang B, Lv R, Lopez-Urias F, Crespi V H, Terrones H, Terrones M 2013 Extraordinary room-temperature photoluminescence in triangular WS2 monolayers Nano Lett. 13 3447-54 doi: 10.1021/nl3026357 [160] Jeong H Y, Jin Y, Yun S J, Zhao J, Baik J, Keum D H, Lee H S, Lee Y H 2017 Heterogeneous defect domains in single-crystalline hexagonal WS2 Adv. Mater. 29 1605043 doi: 10.1002/adma.201605043 [161] Ghorbani-Asl M, Borini S, Kuc A, Heine T 2013 Strain-dependent modulation of conductivity in single-layer transition-metal dichalcogenides Phys. Rev. B 87 235434 doi: 10.1103/PhysRevB.87.235434 [162] Meng L, Zhang Y, Hu S, Wang X, Liu C, Guo Y, Wang X, Yan X 2016 Two dimensional WS2 lateral heterojunctions by strain modulation Appl. Phys. Lett. 108 263104 doi: 10.1063/1.4954991 [163] Yun W S, Han S W, Hong S C, Kim I G, Lee J D 2012 Thickness and strain effects on electronic structures of transition metal dichalcogenides: 2H-M X2 semiconductors (M = Mo, W; X = S, Se, Te) Phys. Rev. B 85 033305 doi: 10.1103/PhysRevB.85.033305 [164] Cerda E, Mahadevan L 2003 Geometry and physics of wrinkling Phys. Rev. Lett. 90 074302 doi: 10.1103/PhysRevLett.90.074302 [165] Vandeparre H, Pieirua M, Brau F, Roman B, Bico J, Gay C, Bao W, Lau C N, Reis P M, Damman P 2011 Wrinkling hierarchy in constrained thin sheets from suspended graphene to curtains Phys. Rev. Lett. 106 224301 doi: 10.1103/PhysRevLett.106.224301 [166] Zhang D-B, Akatyeva E, Dumitric T 2011 Bending ultrathin graphene at the margins of continuum mechanics Phys. Rev. Lett. 106 255503 doi: 10.1103/PhysRevLett.106.255503 [167] Pocivavsek L, Dellsy R, Kern A, Johnson S, Lin B H, Lee K Y C, Cerda E 2008 Stress and fold localization in thin elastic membranes Science 320 912-6 doi: 10.1126/science.1154069 [168] Cai S, Breid D, Crosby A J, Suo Z, Hutchinson J W 2011 Periodic patterns and energy states of buckled films on compliant substrates J. Mech. Phys. Solids 59 1094-114 doi: 10.1016/j.jmps.2011.02.001 [169] Thi Q H, Wong L W, Liu H, Lee C-S, Zhao J, Ly T H 2020 Spontaneously ordered hierarchical two-dimensional wrinkle patterns in two-dimensional materials Nano Lett. 20 8420-5 doi: 10.1021/acs.nanolett.0c03819 [170] Quereda J, San-Jose P, Parente V, Vaquero-Garzon L, Molina-Mendoza A J, Agrait N, Rubio-Bollinger G, Guinea F, Roldan R, Castellanos-Gomez A 2016 Strong modulation of optical properties in black phosphorus through strain-engineered rippling Nano Lett. 16 2931 doi: 10.1021/acs.nanolett.5b04670 [171] Lee J, Yun S J, Seo C, Cho K, Kim T S, An G H, Kang K, Lee H S, Kim J 2021 Switchable, tunable, and directable exciton funneling in periodically wrinkled WS2 Nano Lett. 21 43-50 doi: 10.1021/acs.nanolett.0c02619 [172] Nolte A J, Young Chung J, Davis C S, Stafford C M 2017 Wrinkling-to-delamination transition in thin polymer films on compliant substrates Soft Matter 13 7930-7 doi: 10.1039/C7SM01472D [173] Naumis G G, Barraza-Lopez S, Oliva-Leyva M, Terrones H 2017 Electronic and optical properties of strained graphene and other strained 2D materials: a review Rep. Prog. Phys. 80 1-62 doi: 10.1088/1361-6633/aa74ef [174] Lee C, Wei X, Kysar J W, Hone J 2008 Measurement of the elastic properties and intrinsic strength of monolayer graphene Science 321 385-8 doi: 10.1126/science.1157996 [175] Bertolazzi S, Brivio J, Kis A 2011 Stretching and breaking of ultrathin MoS2 ACS Nano 5 9703-9 doi: 10.1021/nn203879f [176] Tran Khac B-C, DelRio F W, Chung K-H 2018 Interfacial strength and surface damage characteristics of atomically thin h-BN, MoS2, and graphene ACS Appl. Mater. Interfaces 10 9164-77 doi: 10.1021/acsami.8b00001 [177] Ye S, et al 2019 Nanoscratch on single-layer MoS2 crystal by atomic force microscopy: semi-circular to periodical zigzag cracks Mater. Res. Express 6 025048 doi: 10.1088/2053-1591/aaf14f [178] Lu C-P, Li G H, Mao J H, Wang L-M, Andrei E Y 2014 Bandgap, mid-gap states, and gating effects in MoS2 Nano Lett. 14 4628-33 doi: 10.1021/nl501659n [179] Najmaei S, Lei S D, Burke R A, Nichols B M, George A, Ajayan P M, Franklin A D, Lou J, Dubey M 2016 Enabling ultrasensitive photodetection through control of interface properties in molybdenum disulfide atomic layers Sci. Rep. 6 39465 doi: 10.1038/srep39465 [180] Tran M D, Kim J-H, Kim H, Doan M H, Duong D L, Lee Y H 2018 Role of hole trap sites in MoS2 for inconsistency in optical and electrical phenomena ACS Appl. Mater. Interfaces 10 10580-6 doi: 10.1021/acsami.8b00541 [181] Liu J, Goswami A, Jiang K, Khan F, Kim S, McGee R, Li Z, Hu Z, Lee J, Thundat T 2018 Direct-current triboelectricity generation by a sliding Schottky nanocontact on MoS2 multilayers Nat. Nanotechnol. 13 112-6 doi: 10.1038/s41565-017-0019-5 [182] Kim S, Kim T Y, Lee K H, Kim T-H, Cimini F A, Kim S K, Hinchet R, Kim S-W, Falconi C 2017 Rewritable ghost floating gates by tunnelling triboelectrification for two-dimensional electronics Nat. Commun. 8 15891 doi: 10.1038/ncomms15891 [183] Burgo T A D L, Rezende C A, Bertazzo S, Galembeck A, Galembeck F 2011 Electric potential decay on polyethylene: role of atmospheric water on electric charge build-up and dissipation J. Electrost. 69 401-9 doi: 10.1016/j.elstat.2011.05.005 [184] Galembeck F, Burgo T A L, Balestrin L B S, Gouveia R F, Silva C A, Galembeck A 2014 Friction, tribochemistry and triboelectricity: recent progress and perspectives RSC Adv. 4 64280-98 doi: 10.1039/C4RA09604E [185] Ding S, Xiao X, Liu S, Wu J, Huang Z, Qi X, Li J 2019 Detection of interfacial charge transfer in MoS2/PbI2 heterostructures via Kelvin probe force microscope Appl. Phys. A 125 287 doi: 10.1007/s00339-019-2578-9 [186] Bediako D K, Rezaee M, Yoo H, Larson D T, Zhao S Y F, Taniguchi T, Watanabe K, Brower-Thomas T L, Kaxiras E, Kim P 2018 Heterointerface effects in the electrointercalation of van der Waals heterostructures Nature 558 425-9 doi: 10.1038/s41586-018-0205-0 [187] Mertens S F, Hemmi A, Muff S, Groning O, De Feyter S, Osterwalder J, Greber T 2016 Switching stiction and adhesion of a liquid on a solid Nature 534 676 doi: 10.1038/nature18275 [188] Ducke J, Riss A, Paz A P, Seufert K, Schwarz M, Garnica M, Rubio A, Auwarter W 2018 Layered insulator/molecule/metal heterostructures with molecular functionality through porphyrin intercalation ACS Nano 12 2677-84 doi: 10.1021/acsnano.7b08887 [189] Al Balushi Z Y, et al 2016 Two-dimensional gallium nitride realized via graphene encapsulation Nat. Mater. 15 1166-71 doi: 10.1038/nmat4742 [190] Lee H, Ko J-H, Song H C, Salmeron M, Kim Y-H, Park J Y 2018 Isotope- and thickness-dependent friction of water layers intercalated between graphene and mica Tribol. Lett. 66 36 doi: 10.1007/s11249-018-0984-3 [191] Hong Y, Wang S, Li Q, Song X, Wang Z, Zhang X, Besenbacher F, Dong M 2019 Interfacial icelike water local doping of graphene Nanoscale 11 19334-40 doi: 10.1039/C9NR05832J [192] Velasco-Velez J-J, Wu C H, Pascal T A, Wan L F, Guo J, Prendergast D, Salmeron M 2014 The structure of interfacial water on gold electrodes studied by x-ray absorption spectroscopy Science 346 831-4 doi: 10.1126/science.1259437 [193] Dollekamp E, Bampoulis P, Siekman M H, Kooij E S, Zandvliet H J W 2019 Tuning the friction of graphene on mica by alcohol intercalation Langmuir 35 4886-92 doi: 10.1021/acs.langmuir.9b00471 [194] Zhang Y, Zhu W, Hui F, Lanza M, BorcaTasciuc T, Muoz Rojo M 2019 A review on principles and applications of scanning thermal microscopy (SThM) Adv. Funct. Mater. 30 1900892 doi: 10.1002/adfm.201900892 [195] Hwang G, Kwon O 2016 Measuring the size dependence of thermal conductivity of suspended graphene disks using null-point scanning thermal microscopy Nanoscale 8 5280-90 doi: 10.1039/C5NR08097E [196] Menges F, Riel H, Stemmer A, Dimitrakopoulos C, Gotsmann B 2013 Thermal transport into graphene through nanoscopic contacts Phys. Rev. Lett. 111 205901 doi: 10.1103/PhysRevLett.111.205901 [197] Yalon E, et al 2017 Temperature-dependent thermal boundary conductance of monolayer MoS2 by raman thermometry ACS Appl. Mater. Interfaces 9 43013-20 doi: 10.1021/acsami.7b11641 [198] Yasaei P, et al 2017 Interfacial thermal transport in monolayer MoS2 and graphenebased devices Adv. Mater. Interfaces 4 1700334 doi: 10.1002/admi.201700334 [199] Chen Z, Jang W, Bao W, Lau C N, Dames C 2009 Thermal contact resistance between graphene and silicon dioxide Appl. Phys. Lett. 95 161910 doi: 10.1063/1.3245315 [200] Evangeli C, Spiece J, Sangtarash S, MolinaMendoza A J, Mucientes M, Mueller T, Lambert C, Sadeghi H, Kolosov O 2019 Nanoscale thermal transport in 2D nanostructures from cryogenic to room temperature Adv. Electron. Mater. 5 1900331 doi: 10.1002/aelm.201900331 [201] Yasaei P, Murthy A A, Xu Y, Dos Reis R, Shekhawat G S, Dravid V P 2019 Spatial mapping of hot-spots at lateral heterogeneities in monolayer transition metal dichalcogenides Adv. Mater. 31 1808244 doi: 10.1002/adma.201808244