Bottom electrode

Another electrode geometry is the crossed-wire technique (Fig. 3). Here, the bottom electrode is a wire, coated cylindrically with a SAM of UE molecules. The second electrode is a second wire, oriented at right angles, and slowly brought into soft mechanical contact with the monolayer. Wires of 10 pm diameter would interrogate a patch of about 103 molecules [43—45]. 

Fig. 8 (a) The I-V curve measured for a junction consisting of an LB monolayer of margaric acid formed on an Al bottom electrode and a top Au electrode fabricated via the PALO technique, (b) Semilogarithmic plot of current density vs the chain-length of fatty-acid monolayers. The fit to a straight line gives a slope of fl = 0.86 A-1. (Reprinted with permission from [78])... 

Similar results are obtained by using an Hg-based junction under alternating irradiation of the DAE SAM through the semitransparent bottom electrode (Fig. 13). Under this condition a difference between the minimum and the maximum measured currents is 10 [177]. 

Fig. 13 Schematic representation of a photo-active molecular junction containing DAE-based SAM sandwiched between a semitransparent Au bottom electrode and an SAM/Hg-drop top electrode. The electrical response of the junction is measured upon irradiation at different wavelengths through the semitransparent bottom electrode...

Figure 10.17. (a) Schematic diagram of the nanowire dye-sensitized solar cell. Light is incident through the bottom electrode, (b) SEM cross section of a solution-fabricated ZnO nanowire array on fluorine-doped tin oxide. The wires are in direct contact with the substrate. Scale bar, 5 pm. Reproduced from Ref. 41, Copyright 2005, with permission from the Nature Publishing Group. 

A tubular type reactor was used in this experiment as shown in Fig. 2. Two copper electrodes with an area of 100 cm2 each were set in parallel with a gap of 3.5 cm. In order to diminish the eddy current in the gas flow, Teflon inserts were set in a tubular reactor as shown in Fig. 2. The bottom electrode was cooled by circulating water. The temperature of water was almost 19 °C throughout this experiment. 

In any 3D system the key problem is electroding. Morrison et al. use Pd-acetate to yield metallic Pd electrodes (Fig. 6) [9,10]. Probably the ideal combination at present is to use Pd as the outer electrode (which becomes the bottom electrode on the planar FET) and Ru as the inner (top) electrode. The Ru has better wetting characteristics but decomposes for temperatures much above 400 °C hence it cannot be used as the bottom (outer) electrode for SET, which requires a much higher temperature anneal. Ru can be used as the top electrode on either PZT or SET because the device is not subjected to very high temperatures after the top electrode is put down. 

Fig. 6 Electrode geometry for concentric cylindrical electrodes on ferroelectric nanotubes. TE top electrode, BE bottom electrode...

Kymissis I, Dimitrakopoulos CD, Purushshothaman S (2001) High-performance bottom electrode organic thin-film transistors. IEEE Trans Electron Dev 48 1060-1064... 

Fig. 2 Schematic diagram of spin-conserved tunneling via the Julliere model. The top and bottom panels indicate parallel and antiparallel alignment of the magnetization of the top and bottom electrodes, respectively...

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