There is a detached class of substances that is called quasi-conductors. People got known about such substances in the end of the 19th century, but only in the 20th century scientists managed to obtain more knowledge about them. Russian physicists performed a lot of experiments. The results showed that semiconductors may assist to generate the fluctuations and maintain them. But such devices as semiconductor assembly that are utilized today were invented considerably later. The most considerable event in the history of semiconductor devices was the creation of the first transistor by Bell company in 1949. That was the start of the era of semiconductor technologies.
The concern to optical characteristics of semiconductors revived due to research of simulated emission in semiconductors. First laser device was developed with usage of semiconductors. The first variant was based on p - n barriers, the latest ones - on heterojunction.
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