Semiconductors are believed to be a special kind of chemical elements. In the first time this unique class was found in the 1890's but more completely it started to be researched just after the First World War in Europe and in Soviet Union. Russian physicists carried out lots of experiments. The results showed that semiconductors may help to generate the fluctuations and maintain them. But such parts as diodes which are utilized nowadays were invented considerably later. First transistor was developed in Bell's laboratory in 1949. That event impacted on the fast development of semiconductor devices. The intensive research of the features of semiconductors was started at the same time.
Many scientists carry out a great deal of researches simply to gain more knowledge about such feature of semiconductors as stimulated emission. First laser system was created with usage of semiconductors. The first variant was based on p - n barriers, the latest ones - on heterojunction.