Computer Assignment

Computer Assignment

Three essential properties of every material

A material is made from materials first transformed by humans.

Properties: These are the specific characteristics and specific material.

Intrinsic is an adjective "which is within and inside of something"

Physical: the perception that it was a two-way bound material (visual and tactile).

Properties

-mechanical properties, of a material related to the physical deformation of a member

(Hardness, tensile, compression, bending, expansion (elastic zone, plastic zone)

-acoustic: property related to the diffusion of sound (absorption, transmission) of a material,

-thermal: property related to the distribution of thermal energy (conductivity, radiation)

Therefore, a material is selected based on its mechanical, thermal, aesthetic and acoustic properties.

Silicon-based semiconductors

Based on semiconductors have created new devices: thermoelectric, ferroelectric and photoelectric devices. Semiconductors have a large range of applications. In addition to radio engineering in semiconductors developed solar cells, photodiodes, and integrated circuits. All this led to the emergence of new computers and PCs.

Unlike wire carriers in semiconductor materials can be not only electrons, but also the "hole." With the loss of one electron from the atoms of the semiconductor in its orbit is empty space - a "hole" under the influence of an electric field on the crystal "hole" as a positive charge moves in the direction of the vector E, which in fact is due to the rupture of some links and restoration of others. "Holes" can be roughly considered as a particle that carries a positive charge. Since the silicon material is at the heart of modern electronics, by itself is of little use for optical circuits, the researchers turned to a different class of materials - semiconductors III-V. Compounds composed of chemical elements of boron (III group of the periodic table of elements) and of nitrogen (V group) differ remarkable semiconducting properties, and based on them create light-emitting devices - light-emitting diodes and lasers. The modern microelectronics industry is focused mainly on the production of materials based on silicon. Therefore, the introduction of devices from semiconductors III-V in the existing schemes of particular interest: it is possible to reach new heights, without abandoning the old technology. Growing semiconductors III-V is traditionally held at high temperatures - about 700 º C or more, silicon circuits at this temperature would be simply destroyed (Yacobi, 2003).

Semiconductors are one of the most important technological advances have had in this century primarily for allowing an extreme development of general electronics. Its predecessor, the thermionic tube or vacuum ...