What Are Semiconductors?

Since the discovery of electricity, it was known that there are materials that allow the passage of current in one direction and prevent it in the opposite polarity.

In the 1940s the properties of silicon were discovered. Chemical element very abundant in nature, pure silicon tends to form a structure stable crystalline, whose electrons form complete orbits, which does not allow the passage of current electrical. But when you add an impurity from an element that has too many electrons, such as arsenic or too few, such as indium (atoms with incomplete orbits), a material with free electrons is produced, (N-type semiconductor) or, with electron holes (semiconductor Type P).

When an N semiconductor joins with a P semiconductor, we have the NP junction, a diode, which will allow current to pass in one direction, but if the polarity is reversed, the current will not pass. In 1948 the experiments were made to join three layers, in the order NPN and PNP, creating the first transistors.

The discovery of the transistor revolutionized the electronics industry, allowing the first miniaturization of the devices, although they had to continue to be assembled with the rest of the elements in a electronic board.

During the 60s it was discovered that other parts could also be miniaturized and assembled together with semiconductors in the same package: it is the birth of the Integrated circuit, which could take care of all the functions of a larger circuit, but on a much smaller surface, allowing more and more devices to be created. complex.

This allowed a decade later, the first semiconductor-based computer brain to emerge, far superior the one that made the ENIAC computer work, based on vacuum tubes, but infinitely smaller and more efficient; thus being born the microprocessor.