World Association of Zoos and Aquariums

They produce semi-conductors of appointed materials. Their resistance has to be somewhere among that of a conductor and a non-conductor. Whims of temperature or used admixtures also affect the resistance.

The word “admixtures” refers to the other substances added to the material. The finished mixture defines the semi-conductors as thyristors of type-n and type-t.

Diodes as well as transistors are produced of the 2 variants of semi-conductors. Now silicon is surely appearing to be the most wide spread material for producing semi-conductors.

Diode then is the electronic unit created of semiconductor substance. It lets electrical current pass just in a single direction. There is a layer of + (positive) combination, - (negative) combination and pn-transfer appointed as barrier level in each diode. Diodes create electrical schemes converting among direct and alternating current. Because that diodes let current go just in one direction only a part of the series or cycle is completed. People call such a junction a rectifier.

Concerning the light diodes fixed as LED, they are necessary to get light at little voltages not generating heat. Such diodes are present in all kinds of contemporary electronic devices including TV sets or stereo units in order to sign the on mode.

Moore's law gave way to the popularization of thyristors manufactures. What is the main factor to produce complex power semi-conductor equipment at lower cost? Surely lithography. Speaking of optical lithography, it now gives way to the development of new technologies as it has reached its development limit. Presumedly ultraviolet lithography and nano-imprint lithography can turn into the successors to optical lithography. Read the rest of this entry »

Semiconductors are considered to be a unique kind of chemical elements. At first that unique class was found in the 1890's but more completely it started to be discovered just after the First World War in Europe and in Soviet Union. The first successful research was performed by the Russian physicists in 1923. They proved that semiconductors can be used to generate fluctuations. But such devices as semiconductor assembly that are used today were created considerably later. The most significant event in the history of semiconductor devices was the creation of the first transistor by Bell corporation in 1949. Since then a lot of persons all over the world become interested in such type of matter as semiconductors.

The interest to optical features of semiconductors revived because of research of induced emission in semiconductors. First laser system was developed with usage of semiconductors. The first variant was based on p - n barriers, the latest ones - on heterojunction.

Read the rest of this entry »