Semiconductors uses for

Epitaxial crystal growth methods such as molecular beam epitaxy (MBE) and metalorganic chemical vapor deposition (MOCVD) have advanced to the point that active regions of essentially arbitrary thicknesses can be prepared (see Thin films, film deposition techniques). Most semiconductors used for lasers are cubic crystals where the lattice constant, the dimension of the cube, is equal to two atomic plane distances. When the thickness of this layer is reduced to dimensions on the order of 0.01 )J.m, between 20 and 30 atomic plane distances, quantum mechanics is needed for an accurate description of the confined carrier energies (11). Such layers are called quantum wells and the lasers containing such layers in their active regions are known as quantum well lasers (12). 

Fig. 8. A plot of band gap versus lattice constant for Groups 2—16 and 12—16 (II—VI) semiconductors used for the preparation of green and blue lasers.

The ability to respond effectively to an event will require first responders and HAZMAT teams to coordinate thousands of details. Development of new materials for advanced telecommunications and radar could greatly improve the current response standard. Materials that can lead to faster computers, higher-density storage, and more efficient telecommunications are vital. One example of a basic area of research that could have an impact on our ability to respond to a threat is wide bandgap semiconductors, used, for instance, in phased-array radars. The development of shipboard phased-array radar systems over the past few decades has provided the military with a very high degree of situational awareness with respect to airborne targets. 

Table 15.1 Band positions of some common semiconductors used for photocatalytic processes [2, 3, 6, 7, 95].

Lead sulfide (PbS) is a narrow band gap semiconductor used for many optical applications, like IR detectors [1], It is well known that semiconducting properties of PbS can be tailored by reducing the size of particles down to the nanometer scale. Semiconducting properties are greatly affected by the atomic structure. However, the atomic structure of nanoparticles may not be the same as the structure of the same substance in bulk. This paper focuses on study of the atomic structure of PbS nanoparticles. 

GaAs Gallium Arsenide. Semiconductor, used for high-frequency semi-... 

Patterning and fabrication of semiconductors used for electronics devices at nanometer scale are difficult and challenging task to the scientists. Common photolithography techniques are limited in... 

Mixed Metal Oxide Semiconductors Used for Photoelectrodes and Photocatalysts... 

GaAs is probably the most familiar example of 111-V compound semiconductors, used for both highspeed electronics and for optoelectronic devices. Optoelectronics has taken advantage of ternary and quaternary 111-V semiconductors to establish optical wavelengths and to achieve a variety of novel device structures. The ternary semiconductors have the general form A, (with two group III... 

Silicon carbide is an important wide-energy-gap semiconductor used for high power switching devices and as a substrate for some optical devices. It is stable, easily created and the elements from which it is formed are inexpensive and common. 

---