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.
If you require some hi-tech devices as for example power semiconductor devices, it is not a problem, actually. There are lots of producers that offer such. Nowadays it is not possible to perform any experiments without some new technologies that are founded on use of semiconductors.
The main reason why semiconductors are believed to be the divided class is that they have a conductivity that is between the conductivities of metals and isolators. There are some elements which are basically utilized to create the semiconductor devices. They are germanium, selenium, silicon, etc.
For very long period of time semiconductors haven't got the attention of scientists and engineers. The first researches of semiconductors were begun by famous Russian physicist Abram Ioffe. That genius offered some techniques of use of semiconductors and every up to date system is based on such principles. Any semiconductor system has such main features as electron and hole conduction. It is related to the chemical composition of the introduced admixtures. For instance, by utilizing of some admixtures the value of electron conduction can be modified.
Almost every sphere of modern technologies means usage of semiconductors. Diodes, transistors and thyristors are the most frequently used systems. Their sophisticated features are frequently utilized nowadays, but they became widespread just ten years ago. There are devices based on semiconductors which may convert luminous and heat energy into electric power and vice versa. With usage of electric power they can create heat and cold. Such devices as radio receivers, atomic batteries, quantum generator, microprocessors etc include semiconductors. Such devices as disconnectors are commonly utilized in any construction related to the electricity. The usage of semiconductors instead of tube systems permits to lower the overall dimensions and masses of electronic devices. The analogue systems are not equal if we speak about their reliability and power. Tube drops behind.
We can't imagine how the humanity may exist without a lot of devices which are based on usage of semiconductors.
