Three-terminal device

The ideal rectifier or diode is a two-terrninal device that allows current flow in only one direction. The transistor is a three-terminal device in which current flow through two terminals is controlled by the third. Transistors can be used as analogue amplifiers or digital switches. 

Figure 15. (a) SEM image of a three-terminal device with source, drain and gate electrodes. The inset shows in magnification the gap in... 

These results show several parameters for the BJT. In particular Ic is 18.2 mA and Vce is 3.14 volts. Had there been more than one BJT in the circuit, the operating point information would be displayed for all BJTs. Similar information is shown for MOSFET, jFETs, and other three-terminal devices. To close the Text Editor program select File and then Close from the menus ... 

Two-terminal devices might seem more natural for the molecular-scale systems than three-terminal ones because of the technological difficulties in manipulating small structures. Furthermore, chemical assembly of molecular devices usually results in a periodic structure. This observation resulted in the idea to have a two-terminal switch, electronically reconfigurable, where a relatively high voltage (e.g. —2V or +2V in [62], which uses a 2-catenane-based molecule) (Fig. (7a)) is applied to close or open the switch, but a relatively low voltage to read (M). 1 V) [60]. These molecular switches [62], a mono-layer of rotaxane molecules, are not field-activated but can be described as small electro-chemical cells, which are characterized by... 

This chapter describes different synthetic approaches towards the fabrication of candidate molecules for use in molecular electronics applications with an emphasis on thiol end-capped jr-conjugated molecules, followed by a survey of the electronic transmission properties in two- and three-terminal devices. 

Electron Transport in Two- and Three-terminal Molecular Devices... 

Recently, this method has been modified to accommodate also an electrochemical gate [68] in the experimental setup - a situation that resembles a three-terminal device. This setup was used to study the electronic transmission properties of... 

Current fabrication schemes for solid-state three-terminal molecular junctions typically rely on electromigration [78] to produce a nanoscale gap between two metallic electrodes which rests on top of a gate electrode, separated by a thin oxide layer. A schematic representation of a three-terminal device is shown in Fig. 10.15. 

Hot electron spin transistors are hybrid metal/semiconductor devices that rely on spin-dependent transport of hot (nonthermalized) electrons rather than electrons near the Fermi level. The spin-valve transistor (SVT) was the first example of this new class of spintronic devices [128, 129], It has a three-terminal structure consisting of a metallic spin-valve base that is sandwiched between two semiconductor substrates, serving as the emitter and the collector, respectively. The electrons in this device are transported perpendicular to the spin-valve layers at energies just above the collector Schottky barrier height. 

Various matrix addressing schemes are possible with two- and three-terminal devices. For more information, the reader is referred to an early paper of the RCA group (Lechner et al., 1971). Matrix addressing differs from multiplexing in that the LC can be driven at 100% duty factor, maintaining superior optical performance. 

Central to electronics is the IV measurement—that is, the measurement of the electrical current I through a device, as a function of the electrical potential, or bias, or voltage V placed across it. Electrical devices are most often "passive" two-terminal devices (resistors, capacitors, inductors, rectifiers and diodes, NDR devices), or "active" three-terminal devices (triodes, bipolar junction transistors, or field-effect transistors (FET)). 

In most electrochemical measurements of corrosion kinetics a potentiostat is used. This description will cover the rudimentary operation of a potentiostat using the concept of an ideal operational amplifier (op amp) as a basis. An op amp is a three-terminal device as shown in Fig. 16 with two input terminals and one output terminal. A perfect op amp follows five basic rules (19) ... 

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