There is a divided type of substances which is named quasi-conductors. In the first time this unique class was found in the 1890's but more thoroughly it began to be discovered only after the First World War in Europe and in Soviet Union. Russian physicists carried out lots of researches. The results demonstrated that semiconductors can help to generate the fluctuations and maintain them. During further years diodes were ejected by tubes. The most significant event in the history of semiconductor devices was the invention of the first transistor by Bell company in 1949. That was the beginning of the epoch of semiconductor technologies.

A lot of scientists carry out a great deal of experiments simply to get more knowledge about such feature of semiconductors as stimulated emission. By usage of such principles as p - n barriers and heterojunction scientists managed to create laser device in the beginning of the 60's.

Read the rest of this entry »