Resolution enhancement and improved data interpretation in electrostatic force microscopy

Colchero, J.; Gil, Adriana; Baró, A. M.

doi:10.1103/physrevb.64.245403

Cited by 243 publications

(238 citation statements)

References 25 publications

Supporting

Mentioning

227

Contrasting

Order By: Relevance

“…The geometrical factor, given by the function g(D), is a sum of three contributions [220], that of the spherical apex of the tip, that of the conical part, and that of the cantilever:…”

Section: Electrostatic Forcementioning

confidence: 99%

Force measurements with the atomic force microscope: Technique, interpretation and applications

Butt

Cappella

Kappl

2005

Surface Science Reports

3,204

2,949

View full text Add to dashboard Cite

“…The geometrical factor, given by the function g(D), is a sum of three contributions [220], that of the spherical apex of the tip, that of the conical part, and that of the cantilever:…”

Section: Electrostatic Forcementioning

confidence: 99%

Force measurements with the atomic force microscope: Technique, interpretation and applications

Butt

Cappella

Kappl

2005

Surface Science Reports

3,204

2,949

View full text Add to dashboard Cite

“…Measurement of the contact potential difference (V CPD ) between tip and sample proceeded by applying a fixed AC voltage (0.7 V) at 7 kHz to the AFM tip while the sample was held at ground potential. For small amplitudes in the true non-contact regime, and provided that the AC frequency is much smaller than the tip resonance frequency, the shift of the resonance frequency is proportional to the gradient of the electrostatic interaction [32]. A second feedback adjusts the DC bias between tip and sample in order to minimize this interaction and determine V CPD (FM-mode).…”

Section: Electrical Characterization Kpfm and Spvmentioning

confidence: 99%

Direct assessment of p–n junctions in single GaN nanowires by Kelvin probe force microscopy

et al. 2016

View full text Add to dashboard Cite

Making use of Kelvin probe force microscopy, in dark and under ultraviolet illumination, we study the characteristics of p-n junctions formed along the axis of self-organized GaN nanowires (NWs).We map the contact potential difference of the single NW p-n junctions to locate the space charge region and directly measure the depletion width and the junction voltage. Simulations indicate a shrinkage of the built-in potential for NWs with small diameter due to surface band bending, in qualitative agreement with the measurements. The photovoltage of the NW/substrate contact is studied by analysing the response of NW segments with p-and n-type doping under illumination. Our results show that the shifts of the Fermi levels, and not the changes in surface band bending, are the most important effects under above band-gap illumination. The quantitative electrical information obtained here is important for the use of NW p-n junctions as photovoltaic or rectifying devices at the nanoscale, and is especially relevant since the technique does not require the formation of ohmic contacts to the NW junction.2

show abstract

“…For z >≈ 5 nm the capacitances to the tip cone and cantilever exceed that to the tip apex. 19 As a result the response to the sensitive point includes a large "nonlocal" part spread over a lateral area comparable with the size of the tip cone (perhaps 10 μm) and the cantilever (perhaps 30 μm by 150 μm). Many samples, such as 2D films, are sensitive at multiple points or over extended areas, and the combination of the nonlocal response from all sensitive regions produces a large and obfuscating background which in most cases cannot be deconvolved.…”

mentioning

confidence: 99%

Tip-Modulation Scanned Gate Microscopy

Wilson

Cobden

2008

Nano Lett.

View full text Add to dashboard Cite

RECEIVED DATE ()We introduce a technique which improves the sensitivity and resolution and eliminates the nonlocal background of scanned gate microscopy (SGM). In conventional SGM a voltage bias is applied to the atomic force microscope tip and the sample conductance is measured as the tip is scanned. In the new technique, which we call tip-modulation SGM (tmSGM), the biased tip is oscillated and the induced oscillation of the sample conductance is measured. Applied to single-walled carbon nanotube network devices, tmSGM gives sharp, low-noise and background-free images.KEYWORDS Scanned gate microscopy, carbon nanotubes, transconductance, nanotube networks, scanned probe microscopy 2 Atomic force microscopy (AFM) can be used in a number of ways to study the electrical properties of nanoscale structures by applying a voltage, V tip , to the scanning tip. The most common techniques of this kind are electrostatic force microscopy (EFM), conducting AFM, and scanned capacitance microscopy, which can be used to infer for example the local potential, conductivity, and dopant concentration (for a review see 1 ). Less widely known is scanned gate microscopy (SGM), [2][3][4][5][6][7][8][9][10][11][12][13] in which the current through the device is measured while scanning the AFM tip above the sample surface. The tip bias alters the electrostatic potential and free charge density at the surface beneath, so the tip acts as a small scanning local gate electrode. If the sample is nonuniform, the associated change in conductance depends on the tip position and an image of tip bias sensitivity ('local transconductance') vs position can be constructed, giving information about such things as current distribution, location of potential barriers, and free charge density in the sample.One reason SGM is relatively rarely used is that it is limited by the slow (reciprocal) decay of capacitance with distance, leading to a large nonlocal background signal from the capacitance to the tip cone and the cantilever. A second reason is that for many systems of interest, such as thin films, the total conductance is only weakly dependent on the modification of a small region by the tip, and so the signal is too small to be practical. This is not a problem for one dimensional (1D) structures such as carbon nanotubes and nanowires where the sensitivity to local gating can be large because a small part of the nanotube can limit the total conductance. For this reason SGM has been used extensively on nanotube devices, where it has revealed the disordered background potential in semiconducting nanotubes, 2, 3 resistance contributions due to defects 4,5 and Schottky barriers at the contacts, 6 resonant energy dependence of scattering by defects, 7 and single electron charging effects. 8 SGM has also been used successfully on nanowire devices 9 and low temperature systems such as quantum point contacts 10-12 and microconstrictions 13 in two dimensional (2D) electron gases where sensitivity to a local perturbation is enhanced. 3Here we employ a simple ...

show abstract

Resolution enhancement and improved data interpretation in electrostatic force microscopy

Cited by 243 publications

References 25 publications

Force measurements with the atomic force microscope: Technique, interpretation and applications

Force measurements with the atomic force microscope: Technique, interpretation and applications

Direct assessment of p–n junctions in single GaN nanowires by Kelvin probe force microscopy

Tip-Modulation Scanned Gate Microscopy

Contact Info

Product

Resources

About