Electronic device operation

CNT based FETs can outperform the current FET technologies in many ways however, one of the most interesting properties of carbon nanotubes is the ballistic transport of electrons [178], which opens the possibility of constructing FETs that can operate at extremely high frequencies, making them suitable for the next generation electronic devices. Operation of SWCNT transistors has been demonstrated at microwave frequencies (see Fig. 21) [179] and more recently the operation of an SWCNT transistor in the terahertz frequency range was demonstrated [148]. 

At the present time the fastest electronic devices operate in the picosecond range ( 10 12 s), slow in comparison to the duration of optical pulses which can be as short as a femtosecond (10 15 s). The communications systems engineer describes the use of electronics for signal processing as the electronics bottleneck . 

Silicon dominates microelectronics and there is no any other semiconductor to replace it in the foreseeable future. The only exception may be special applications, such as high temperature electronic devices operating above 200 °C, where silicon carbide represents a promising material which can be processed with a silicon-compatible technology. 

Here we attempt to relate the dynamic processes, measured by time correlation functions, to their characteristic timescales in the temperature range 300-600 K, relevant to organic electronic devices operation and fabrication. It is worth mentioning that in such applications, beyond the stmctiunl dynamics treated here, the timescales associated with charge or exciton dynamics are also very important, in particular for assessing the coupling between electron and nuclear dynamics. 

Diamond and Refractory Ceramic Semiconductors. Ceramic thin films of diamond, sihcon carbide, and other refractory semiconductors (qv), eg, cubic BN and BP and GaN and GaAlN, are of interest because of the special combination of thermal, mechanical, and electronic properties (see Refractories). The majority of the research effort has focused on SiC and diamond, because these materials have much greater figures of merit for transistor power and frequency performance than Si, GaAs, and InP (13). Compared to typical semiconductors such as Si and GaAs, these materials also offer the possibiUty of device operation at considerably higher temperatures. For example, operation of a siUcon carbide MOSFET at temperatures above 900 K has been demonstrated. These devices have not yet been commercialized, however. 

These are unidirectional and uncontrollablet static electronic devices and used as static switches and shown in Figure 6.14. A diode turns ON at the instant it becomes forward biased and OFF when it becomes reverse biased. By connecting them in series parallel combinations, they can be made suitable for any desired voltage and current ratings. Whether it is a transistor scheme or a thyristor scheme, they are used extensively where a forward conduction alone is necessary and the scheme calls for only a simple switching, without any control over the switching operation. They are used extensively in a rectifier circuit to convert a fixed a.c. supply to a fixed d.c. supply. 

MIM or SIM [82-84] diodes to the PPV/A1 interface provides a good qualitative understanding of the device operation in terms of Schottky diodes for high impurity densities (typically 2> 1017 cm-3) and rigid band diodes for low impurity densities (typically<1017 cm-3). Figure 15-14a and b schematically show the two models for the different impurity concentrations. However, these models do not allow a quantitative description of the open circuit voltage or the spectral resolved photocurrent spectrum. The transport properties of single-layer polymer diodes with asymmetric metal electrodes are well described by the double-carrier current flow equation (Eq. (15.4)) where the holes show a field dependent mobility and the electrons of the holes show a temperature-dependent trap distribution. 

A number of material suppliers offer information on their products on electronic devices (floppy discs, CDs, etc.) for use on personal computers. An important one, called Campus, is a database concept started by four German material manufacturers who use a uniform software. This database, initially developed jointly by BASF, Bayer, Hoechst, and Hulls, provided for other manufacturers to join. The present consortium has more than 50 materials suppliers worldwide. It is given in the form of diskettes in German, English, French, Italian, or Spanish. Each diskette contains the uniform test and evaluation program and the range of the respective material producers. It runs on IBM-compatible personal computers under the MS-DOS operating system. 

All of the optical and infrared focal plane arrays are solid state electronic devices, and to fully understand their physics and operation, one should have a solid foundation in the solid state electronics. An excellent reference is ... 

Longer uninterrupted operation of a number of smaller electronic devices (mobile phones, portable PCs, etc.) will require the ordinary batteries driving them to be replaced by power sources of higher capacity. 

Let us start with a definition. Semiconductor chemical sensor is an electronic device designed to monitor the content of particles of a certain gas in surrounding medium. The operational principle of this device is based on transformation of the value of adsorption directly into electrical signal. This signal corresponds to amount of particles adsorbed from surrounding medium or deposited on the surface of operational element of the sensor due to heterogeneous diemical reaction. 

This technique will allow compression of a 100-femtosecond pulse down to 12 femtoseconds or even to 8 femtoseconds. (A femtosecond is a millionth of a billionth of a second or 1 x 10-15 s.) Pulse compression can be used to study chemical reactions, particularly intermediate states, at very high speeds. Alternatively, these optical pulses can be converted to electrical pulses to study electrical phenomena. This aspect, of course, is of great interest to people in the electronics industry because of their concern with the operation of high-speed electronic devices. It also is of great interest to people who are trying to understand the motion of biological objects such as bacteria. 

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