A general and simple method for evaluating the electrical transport performance of graphene by the van der Pauw–Hall measurement

ABSTRACTIn this study we analyze the electrical behavior of a junction formed by an ultraheavily Ti implanted Si layer processed by a Pulsed Laser Melting (PLM) and the non implanted Si substrate. This electrical behavior exhibits an electrical decoupling effect in this bilayer that we have associated to an Intermediate Band (IB) formation in the Ti supersaturated Si layer. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) measurements show a Ti depth profile with concentrations well above the theoretical limit required to the IB formation. Sheet resistance and Hall mobility measurements in the van der Pauw configuration of these bilayers exhibit a clear dependence with the different measurement currents introduced (1µA-1mA). We find that the electrical transport properties measured present an electrical decoupling effect in the bilayer as function of the temperature. The dependence of this effect with the injected current could be explained in terms of an additional current flow in the junction from the substrate to the IB layer and in terms of the voltage dependence in the junction with the measurement current.

Download Full-text

Van der Pauw Hall Measurement on Intended Doped ZnO Films for p-Type Conductivity

Chinese Physics Letters ◽

10.1088/0256-307x/27/6/067203 ◽

2010 ◽

Vol 27 (6) ◽

pp. 067203 ◽

Cited By ~ 5

Author(s):

Guo Yang ◽

Liu Yac-Ping ◽

Li Jun-Qiang ◽

Zhang Sheng-Li ◽

Mei Zeng-Xia ◽

...

Keyword(s):

Hall Measurement ◽

Zno Films ◽

Type Conductivity ◽

Doped Zno ◽

Van Der Pauw ◽

P Type

Download Full-text

Electrical Transport Properties of Ga(AsxSb1−x) and (GaxIn1−x)Sb Alloys under Hydrostatic Pressure

Canadian Journal of Physics ◽

10.1139/p75-136 ◽

1975 ◽

Vol 53 (11) ◽

pp. 1071-1077 ◽

Cited By ~ 3

Author(s):

Stanley D. Rosenbaum ◽

John C. Woolley

Keyword(s):

Hydrostatic Pressure ◽

Hall Coefficient ◽

Electrical Transport ◽

Room Temperature ◽

Energy Separation ◽

Band Model ◽

Electrical Transport Properties ◽

Van Der Pauw ◽

Directional Freezing ◽

Good Agreement

Homogeneous polycrystalline n type samples of the alloys Ga(AsxSb1−x) and (GaxIn1−x)Sb have been prepared from a stoichiometric melt by directional freezing methods. Room temperature measurements of electrical conductivity and Hall coefficient as a function of hydrostatic pressure up to 12 kbars have been made on samples of different composition by means of the van der Pauw technique, all specimens used in the measurements being carefully selected to avoid the presence of grain boundary effects. The experimental curves of conductivity and Hall coefficient as a function of pressure have been fitted to a two conduction band model with various band parameters taken as adjustable. The curves thus fitted give consistent values of E12, the energy separation of the two bands, as a function of x. For (GaxIn1−x)Sb, the E12 values are in good agreement with those obtained previously from measurements as a function of temperature, no previous values having been published for Ga(AsxSb1−x). Approximate values for the coupling coefficient D12 of the alloys are also obtained.

Download Full-text

Polynomial-interpolation algorithm for van der Pauw Hall measurement in a metal hydride film

Measurement Science and Technology ◽

10.1088/0957-0233/19/10/105106 ◽

2008 ◽

Vol 19 (10) ◽

pp. 105106

Author(s):

D W Koon ◽

J R Ares ◽

F Leardini ◽

J F Fernández ◽

I J Ferrer

Keyword(s):

Metal Hydride ◽

Polynomial Interpolation ◽

Hall Measurement ◽

Interpolation Algorithm ◽

Van Der Pauw

Download Full-text

A simple way for producing holographic filters suitable for image improvement

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100108271 ◽

1978 ◽

Vol 36 (1) ◽

pp. 226-227

Author(s):

K.-H. Herrmann ◽

E. Reuber ◽

P. Schiske

Keyword(s):

Transfer Functions ◽

Diffraction Order ◽

Lateral Position ◽

Simple Method ◽

Spatial Frequencies ◽

Resolution Electron ◽

Wiener Filters ◽

Image Improvement ◽

Optical Reconstruction ◽

Set Up

Aposteriori deblurring of high resolution electron micrographs of weak phase objects can be performed by holographic filters [1,2] which are arranged in the Fourier domain of a light-optical reconstruction set-up. According to the diffraction efficiency and the lateral position of the grating structure, the filters permit adjustment of the amplitudes and phases of the spatial frequencies in the image which is obtained in the first diffraction order.In the case of bright field imaging with axial illumination, the Contrast Transfer Functions (CTF) are oscillating, but real. For different imageforming conditions and several signal-to-noise ratios an extensive set of Wiener-filters should be available. A simple method of producing such filters by only photographic and mechanical means will be described here.A transparent master grating with 6.25 lines/mm and 160 mm diameter was produced by a high precision computer plotter. It is photographed through a rotating mask, plotted by a standard plotter.

Download Full-text

Rotary Beveling for In Situ Thin-Section Microscopy of Cell Cultures

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100099192 ◽

1981 ◽

Vol 39 ◽

pp. 550-551

Author(s):

Dean A. Handley ◽

Jack T. Alexander ◽

Shu Chien

Keyword(s):

Cell Growth ◽

Cell Cultures ◽

Molecular Interactions ◽

Convenient Method ◽

Petri Dish ◽

Simple Method ◽

Thin Section Microscopy ◽

Thin Sectioning ◽

Organic Fluids

In situ preparation of cell cultures for ultrastructural investigations is a convenient method by which fixation, dehydration and embedment are carried out in the culture petri dish. The in situ method offers the advantage of preserving the native orientation of cell-cell interactions, junctional regions and overlapping configurations. In order to section after embedment, the petri dish is usually separated from the polymerized resin by either differential cryo-contraction or solvation in organic fluids. The remaining resin block must be re-embedded before sectioning. Although removal of the petri dish may not disrupt the native cellular geometry, it does sacrifice what is now recognized as an important characteristic of cell growth: cell-substratum molecular interactions. To preserve the topographic cell-substratum relationship, we developed a simple method of tapered rotary beveling to reduce the petri dish thickness to a dimension suitable for direct thin sectioning.

Download Full-text