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The wide range of prospective technological applications in electronics, optics, biomedicine, mechanics, and integrated nanostructures are of great interest. The two fundamental steps in nanotechnological processes include, control of nanocrystal structures, and arrangement of nanostructures within the building blocks of special nanodevices.

The usage of the semiconductor Hg(sub 1-x)Cd(sub x)Te (MCT) in infrared detector technology, for imaging arrays in both scanning and staring configurations, is discussed. By using the transmission electron microscopy (TEM), the defect generation was characterized in planar view and cross section geometries.

The development of a novel chip-based multianalyte detection system with a cardiac theme is reported. This work follows the initial reports of 'electronic taste chips' whereby multiple solution-phase analytes such as acids, bases, metal cations, and biological cofactors were detected and quantitated. The newly fashioned 'cardiac chip' exploits a geometry that allows for isolation and entrapment of single polymeric spheres in micromachined pits while providing to each bead the rapid introduction of a series of reagents/washes through microfluidic structures. The combination of these miniaturized components fosters the completion of complex assays with short analysis times using small sample volumes. Optical signals derived from single beads are used to complete immunological tests that yield outstanding assay characteristics. The power and utility of this new methodology is demonstrated here for the simultaneous detection of the cardiac risk factors, C-reactive protein and interleukin-6, in human serum samples. This demonstration represents the first important step toward the development of a useful cardiac chip that targets numerous risk factors concurrently and one that can be customized readily for specific clinical settings.

In recent years, extensive semiconductor development has gone into both bipolar and MOS structures for medium-voltage (MV) applications. However, the progression of MOS structures in MV applications has been difficult and the issues of module isolation, reliability, and dv/dt and motor/bearing life continue to limit its acceptance in these applications. A more suitable device structure and the natural choice for MV applications is the bipolar thyristor structure. The device that has been in use for many years, the gate-turn-off thyristor, is being replaced by the gate-commutated thyristor (GCT). So far, the GCT has been only thought of as fulfilling the needs for the voltage-source topology. However, the symmetric GCT (SGCT) is viable and has significant advantages when implemented in a pulsewidth-modulated current-source inverter (PWM-CSI). This paper will describe the design and characteristics of an 800-A 6.5-kV SGCT and the effect of its implementation in a PWM-CSI. These effects include operation at a higher switching frequency, elimination/reduction and modification of the snubber circuitry, reduction in size of the passive components, and a major impact on the cost of the converter. The paper includes experimental results on a 4160-V 1250-hp PWM-CSI ac drive. Index Terms-Current-source converter, hard-driven gate-turn-off thyristor, medium-voltage applications, power semiconductor devices, symmetric gate-commuted thyristor, variable-speed drives.

In this paper, reverse-recovery failure modes in modern fast power diodes are investigated. By the aid of semiconductor device simulation tools, a better view is obtained for the physical process, and operating conditions at which both diode snappy recovery and dynamic avalanching occur during the recovery period in modern high-frequency power electronic applications. The work presented here confirms that the reverse-recovery process can by expressed by means of diode capacitance effects which influence the reverse-recovery characteristics. The paper also shows that the control of the carrier gradient and the remaining stored charge in the drift region during the recovery phase influence both failure modes and determine if the diode exhibits soft, snappy, or dynamic avalanche recovery characteristics. Index Terms--Dynamic avalanche, freewheeling diode, snappy recovery.

Linearity characteristics of GaAs heterojunction bipolar transistors (HBTs) are studied through measurement and analysis. Third-order intermodulation distortion behavior of HBTs is examined on devices with various epilayer designs and at various bias points, loads, and frequencies. Calculations from an analytical model reveal a strong bias and load dependence of third-order intercept point (IP3) on the nonlinearities from transconductance and the voltage dependence of base-collector capacitance. However, a simple model is not able to predict the fine details of IP3 with bias. A large-signal HBT model with an accurate description of the base-collector charge is shown to account for the measured trends. The base-collector charge function accounts for the modulation of base-collector capacitance with current, electron velocity modulation, and Kirk effect (base pushout) for GaAs-based HBTs. A detailed study of the influence of collector design on linearity is also presented. Index Terms--Heterojunction bipolar transistors (HBTs), intermodulation distortion, nonlinear distortion, semiconductor device modeling.

A scalable large-signal model for heterojunction bipolar transistors (HBTs) is presented in this paper. It allows exact modeling of all transistor parameters from single-finger elementary cells to multifinger power devices. The scaling rules are given in detail. The model includes a new collector description, which accounts for modulation of base--collector capacitance [C.sub.jc], as well as for base and collector transit times due to temperature effects and high-current injection. The model is verified by comparison with measurements of GaInP/GaAs HBTs. Index Terms--Equivalent circuits, heterojunction bipolar transistors, semiconductor device modeling, semiconductor device thermal factors.

It seems to flout the laws of physics, but scientists have found a loophole in the rules that govern diffraction. By exploiting entanglement, the quintessential 'Spooky' phenomenon in quantum mechanics, [...]

The scalability of power performance of AlGaN/GaN MODFETs with large gate periphery, as necessary for microwave power devices, is addressed in this paper. High-frequency large-signal characteristics of AlGaN/GaN MODFETs measured at 8 GHz are reported for devices with gatewidths from 200 [micro]m to 1 mm. 1-dB gain compression occurred at input power levels varying from -1 to + 10 dBm as the gatewidth increased, while gain remained almost constant at ~17 dB. Output power density was ~1 W/mm for all devices and maximum output power (29.9 dBm) occurred in devices with 1-mm gates, while power-added efficiency remained almost constant at ~30%. The large-signal characteristics were compared with those obtained by dc and small-signal S-parameters measurements. The results illustrate a notable scalability of AlGaN/GaN MODFET power characteristics and demonstrate their excellent potential for power applications. Index Terms--Device measurements, microwave power amplifiers, MODFETs, semiconductor.

A cascaded two-level converter is proposed which utilizes two six-transistor inverters and is capable of producing voltages which are identical to those of three-level and four-level converters. Since the machine voltages are the same, the converter performance is the same as is verified through laboratory tests. The advantages and disadvantages of the proposed cascaded converter are explored. The proposed converter is simpler to construct and offers more non-redundant switching states per number of active semiconductors than standard multi-level converters.

Typically, semiconductors are etched with the use of chemicals, which can cause various etching errors. On the other hand, the typical process of feature size or height control starts with [...]

The usage of transparent oxide semiconductors (TOSs), such as zinc oxide (ZnO), indium-zinc oxides (IZO), and so on, for thin-film transistors (TFTs) has garnered a considerable amount of attention. The [...]

Memory storage technology can be broadly classified into two types: volatile and nonvolatile memories. Volatile memories are those which lose their stored data if the power supply is removed. They [...]

The first discotic system with an unusual self-organization behavior over long-range to form spherulite textures is reported. Because of its processability and modulated, self-organization behavior, the system is a promising candidate as an active component of electronic devices.

A simple method 'hot lift off' procedure is introduced for creating micropatterns in organic semiconductor microcystalline films, which is used to fabricate organic field effect transisters (OFETs). This is an attractive alternative approach for conventional organic semiconductor microsrystalline patterning technique.

University of Michigan, Ann Arbor, researchers took a step to make high-performance thermoelectric materials that convert waste heat to electricity. A semiconducting material was engineered at the level of its [...]

Researchers at Massachusetts Institute of Technology, Cambridge, developed a new process to produce quantum dots with four important qualities: uniform sizes and shapes; bright emissions (producing close to 100% emission [...]

Compost oxygen levels can be continuously measured using a semiconductor gas sensor probe which is unaffected by high temperatures and cross contamination. The probe is designed for longterm use and can work in temperatures of up to 105 degrees centigrade. Its design, illustrated, contains sensors for relative humidity, temperature and oxygen. Sensor testing conditions are described.

Researchers at Lawrence Berkeley National Laboratory (Berkeley Lab) and University of California (UC) Berkeley developed a technology that enables low-cost, high-efficiency solar cells to be made from virtually any semiconductor [...]

J. Am. Chem. Soc. doi:10.1021/ja804164y (2008) Carbon nanotubes produced by the commonly used high-pressure carbon monoxide method are normally one-third metallic or semi-metallic and two-thirds semiconductor, and of various diameters. [...]