Semiconductor (semiconductor), refers to the conductivity at room temperature between the conductor (conductor) and insulator (insulator) materials. Semiconductors are widely used in radios, televisions, and temperature measurement.
such as the diode is the use of semiconductor devices. Semiconductor is a conductivity can be controlled, the range can be from the insulator to the conductor between the material. The importance of semiconductors is enormous, both from the point of view of technological and economic development.
The core units of most of today's electronics, such as computers, cellular telephones, and digital recorders, are closely related to semiconductors. Common semiconductor materials are silicon, germanium, gallium arsenide, etc., and silicon is a variety of semiconductor materials, the most influential one in the commercial application.
Classification:
Semiconductor materials are many, according to the chemical composition can be divided into elemental semiconductor and compound semiconductor two categories.
Germanium and silicon are the most commonly used elemental semiconductors; compound semiconductors, including the Ⅲ and Ⅴ compounds (gallium arsenide, gallium phosphide, etc.), Ⅱ and Ⅵ compounds (cadmium sulfide, zinc sulfide, etc.), oxides (manganese, chromium, iron, copper oxides), as well as Ⅲ - Ⅴ compounds and Ⅱ - Ⅵ compounds composed of solid solutions (gallium, aluminum, arsenic and arsenic phosphorus, etc.).
In addition to the above crystalline semiconductors, there are amorphous glass semiconductors, organic semiconductors and so on.
The classification of semiconductors, according to its manufacturing technology can be divided into: integrated circuit devices, discrete devices, optoelectronic semiconductors, logic ICs, analog ICs, storage and other major categories, in general these will also be divided into smaller categories.
Additionally, there is a method of categorizing ICs, LSIs, VLSIs (very large LSIs), and their sizes according to their application areas and design methods, although these are not commonly used. In addition, there is also a method of classification according to the signals handled, which can be divided into analog, digital, analog-digital hybrid, and function.
Expanded Information:
History:
The discovery of semiconductors actually goes back a long way.
In 1833, the British scientist Faraday, the father of electronics, was the first to discover that the resistance of silver sulfide with the change in temperature is different from the general situation of the metal, in general, the resistance of the metal with the temperature increases, but Baraday found that the resistance of the silver sulfide material with the rise in temperature and decrease. This is the first discovery of the semiconductor phenomenon.
Soon, in 1839, France's Becquerel found that semiconductors and electrolytes in contact with the formation of the junction, in the light will produce a voltage, which is later known as the photovoltaic effect, which was found to be the second feature of the semiconductor.
In 1873, Britain's Smith found that selenium crystal material in the light of the conductivity increased photoconductivity effect, which is another characteristic of semiconductors.
The four effects of semiconductors, (jianxia Hall effect of the residual performance - the discovery of the four companion effects) although in 1880 before the successive discovery, but the semiconductor this term is probably to 1911 was Kaunibeg and Wise first used. And summarizing these four properties of semiconductors was not completed until December 1947 by Bell Labs.
In 1874, Germany's Braun observed that the conductivity of certain sulfides and the direction of the added electric field is related to the direction of the electric field, that is, its conductivity has a directionality, add a positive voltage at both ends of it, it is conductive; if the polarity of the voltage is reversed, it does not conduct electricity, which is the semiconductor's rectification effect, but also semiconductors are unique to the third property. In the same year, Schuster also discovered the rectification effect of copper and copper oxide.
Many people will question why it took so many years for semiconductors to be recognized. The main reason was that the materials were impure at the time. Without good materials, many of the problems associated with materials are difficult to articulate.
References:
Baidu Encyclopedia-Semiconductor