Surface potential microscopy/Kelvin probe

Many-pass techniques Electric Force Microscopy (EFM) Scanning Capacitance Microscopy (SCaM) Kelvin Probe Microscopy (SKM) DC Magnetic Force Microscopy (DC MFM) AC Magnetic Force Microscopy (AC MFM) Dissipation Force Microscopy-Scanning Surface Potential Microscopy (SSPM) Scanning Maxwell Stress Microscpy (SMMM) Magnetic Force Microscopy (MFM) Van der Waals Force Microscopy (VDWFM)... 

While the previously described techniques both require extrapolation of measured data in order to calculate the contact resistance, Kelvin probe force microscopy (KFM, also known as scanning surface potential microscopy or scanning potenti-ometry) can be used to determine the source and drain contributions to the contact resistance directly. In KFM, a conductive atomic force microscope (AFM) tip is scanned over the operational OFET channel twice. On the first pass, the topography... 

Bocquet, F., Nony, L, Loppacher, C., and Glatzel, T. (2008) Analytical approach to the local contact potential difference on (001) ionic surfaces implications for Kelvin probe force microscopy. Phys. Rev. B, 78, 035410. 

A further spatially resolved method, also based on work function contrast, is scanning Kelvin probe microscopy (SKPM). As an extended version of atomic force microscopy (AFM), additional information on the local surface potential is revealed by a second feedback circuit. The method delivers information depending on the value (p (p(x) + A x). Here, A(zS(x) is the difference in work function between the sample and the AFM tip and cp(x) is the local electric potential [12]. (p x) itself gives information on additional surface charges due to... 

For all nc-AFM measurements, a Kelvin probe force microscopy (KPFM) feedback controller was additionally activated for simultaneous topographic imaging [19]. In order to compensate for electrically or electronically induced artefacts, an ac voltage was applied between tip and sample and used in combination with lock-in techniques and a feedback controller to compensate for the contact potential difference (CPD) between tip and sample. With this method, nc-AFM is assiued to image the sample topography without any artefacts originating from different local surface potentials [20]. 

Puntambekar, K.P., Pesavento, PV. and Frisbie, C.D., Surface potential profiling and contact resistance measurements on operating pentacene thin-fikn transistors by Kelvin probe force microscopy, Appl. Phys. Lett, 83, 5539-5541, 2003. 

Under certain circumstances, the electrode potential of a surface determines its Volta potential, and thus SKP microscopy allows measurement of local electrode or corrosion potentials. Conventional scanning electrochemical reference electrode techniques require a finite electrolytic resistance between sample and reference electrode, whereas the Kelvin Probe operates across a dielectric medium of infinite... 

AFM also provides information on the lateral distribution of the surface potential over a sample. The term surface potential in this context means the potential difference between the sample and a conducting probe that is positioned close to the sample. This is so-called Kelvin probe force microscopy (KFM) [46], which offers a possibility of distinguishing between regions with different chemical natures or compositions. For example. 

The force harmonics F and F2 are both proportional to the capacitance gradient SCfSz. More importantly, the first harmonic of the electric force Fi is directly proportional to the surface potential Vs- At a given position, this surface potential can be measured directly by varying Vdc, so that the first harmonic of the electric force Ft is equal to zero. In this way, the DC voltage, necessary to compensate the first harmonic, is equal to the surface electric potential Vs- This is the principle of the Kelvin Probe Microscopy. Furthermore, by dividing the first harmonic Fi by the second harmonic F2... 

Figure 6. Surface potential of a DT-PFDT gradient and pure DT- and PFDT-SAM measured by means of Kelvin Probe Force Microscopy (KPFM) (The r-axis error bars represent the uncertainty of the position along the gradient sample).

Y., Fuyuki, T., Okuda, M. and Yamashita, I. (2007) Surface potential difference of biomineralized inorganic nanodot by Kelvin probe force microscopy. Japanese Journal of Applied Physics, 46, 5647-51. 

Enevoldsen, G.H., Glatzd, T., Christensen, M.G., Lauritsen, J.V., and Besenbacher, F. (2008) Atomic scale Kelvin probe force microscopy studies of the surface potential variations on the TiO2(110) surface. Phys. Rev. Lett., 100, 236104. 

Liscio, A., Palermo, V., Mullen, K., and Samori, P. (2008) Tip-sample interactions in Kelvin probe force microscopy quantitative measurement of the local surface potential. J. Phys. Chem. C, 112, 17368-17377. 

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