Semiconductors are believed to be a unique class of chemical elements. Such class was discovered in early 1980's but there were no needed technologies to carry on the further experiments. The analysis of semiconductors was carried on only in the 1920's. Russian scientists carried out a lot of researches. The results showed that semiconductors can help to generate the fluctuations and maintain them. But such parts as semiconductor assembly that are utilized today were created considerably later. Only in the beginning of the 60's with the invention of transistors in 1949 the wide usage of crystal detectors started. Since then a lot of people all over the world become interested in such kind of matter as semiconductors.

Many scientists carry out a huge amount of experiments just to get more knowledge about such characteristic of semiconductors as stimulated emission. By means of such principles as p ? n barriers and heterojunction scientists managed to create laser device in the beginning of the 60's.

Today we may see a huge amount of various diodes that operate with help of use of semiconductors. Today it is impossible to carry out any experiments without some new technologies which are based on use of semiconductors.

The basic reason why semiconductors are believed to be the divided kind is that they have got a conductivity that is between the conductivities of metals and isolators. Such matters as germanium, silicon, selenium and some others are considered to be semiconductors.

Physicists haven't been interested in semiconductors for very long period of time. Abram Ioffe is a soviet physicist who started carrying out different experiments in area of semiconductors. He found that this wonderful type of matter has some special features and described how they can be used. There are electron conduction and hole conduction provided by semiconductor systems. Such characteristics can be changed by means of adding some admixtures or modifying temperature. For instance, by utilizing of some admixtures the value of electron conduction may be changed.

Almost every sphere of newest technologies implies use of semiconductors. Diodes, transistors and thyristors are the most often utilized devices. Their unique features are frequently utilized nowadays, but they became widespread just ten years ago. There is a possibility to convert almost every kind of energy into electric power by usage of semiconductors. Heat and cold may be produced by some types of semiconductors. Such devices as radio receivers, atomic batteries, quantum generator, microprocessors etc comprise semiconductors. Almost every engineer who works in company related to electricity should know how important the disconnectors are. The use of semiconductors instead of tube systems allows to lower the overall dimensions and masses of electronic systems. The analogue devices are not equal if we speak about their reliability and power. Tube falls behind.

There are many various systems nowadays, that significantly ease our life and all these inventions appear just thanks to the semiconductor systems.