There is a detached type of substances which is named quasi-conductors. This type was discovered in early 1980's but there were no needed technologies to carry on the further researches. The analysis of semiconductors was continued just in the 1920's. Russian physicists carried out lots of experiments. The results demonstrated that semiconductors can help to generate the fluctuations and maintain them. There was no possibility to develop some sophisticated devices as igbt modules. First transistor was created in Bell's laboratory in 1949. That event influenced the quick development of semiconductor devices. That was the beginning of the era of semiconductor technologies.

Many physicists perform a great deal of researches just to get more knowledge about such feature of semiconductors as stimulated emission. First laser system was developed with usage of semiconductors. The first version was based on p - n barriers, the latest ones - on heterojunction.

Today we can see a huge amount of various asymmetric GTO thyristors that work with help of use of semiconductors. Semiconductor substances have been researched for not so long but radio electronics and many other sciences can't do without usage of them.

Semiconductors are a broad kind of matters that are characterized by the value of conductivity which lies between the conductivities of metals and isolators. Such matters as germanium, silicon, selenium and some others are believed to be semiconductors.

It sounds a little strange but physicists didn't want to carry out researches of semiconductors for a long time. Abram Ioffe is a Russian scientist that began carrying out different researches in area of semiconductors. He found that semiconductors are the divided type of crystals with some definite characteristics. There are electron conduction and hole conduction provided by semiconductor systems. These characteristics may be modified by usage of adding some admixtures or changing temperature. The admixtures affect significantly on the electron conduction of the semiconductors.

Almost every area of newest technologies implies usage of semiconductors. Diodes, transistors and thyristors are the most often utilized systems. The broad application of semiconductors started not so long ago but today they are really widely used. There is an ability to transform almost every kind of energy into electric power by usage of semiconductors. With help of electric power they may create heat and cold. Such systems as radio receivers, atomic batteries, quantum generator, microprocessors etc comprise semiconductors. Almost every engineer who works in company connected to electricity ought to know how significant the fuses are. If we match devices equipped with semiconductors and tube devices we will see that semiconductors are significantly smaller and lighter. The analogue systems are not equal in case we speak about their reliability and power. Tube drops behind.

We can't imagine how the humanity can exist without lots of devices which are based on utilizing of semiconductors.