Any modern chip, so, and all digital equipment does not do without transistor. 70 years ago in radio engineering electron tubes which possessed a set of shortcomings were used. They needed to be replaced with something more durable and economical in the consumption plan of energy.
The transistor is manufactured on the basis of semiconductors. Long time them was not recognized, using for creation of various devices only conductors and dielectrics. Similar devices had a set of shortcomings: low efficiency, high energy consumption and fragility. Studying properties of semiconductors became a turning point in the history of electronics.
Electronic conductivity of various substances
All substances on the ability to carry electric current are divided into three big groups: metals, dielectrics and semiconductors. Dielectrics are called so because are almost not capable to carry current. Metals have the best conductivity thanks to existence in them of free electrons which chaotically move among atoms. At application of external electric field these electrons will begin to move towards positive potential. On metal there will pass current.
Semiconductors are capable to carry current worse than metals, but it is better than dielectrics. In such substances exist main (electrons) and non-core (hole) carriers of electric charge. What it hole? This lack of one electron on an external atomic orbital. The hole is capable to move on material. By means of special impurity, donorny or acceptor, it is possible to increase significantly quantity of electrons and holes in initial substance. The N-semiconductor can be received, having created surplus of electrons, and the p-conductor - by means of surplus of holes.
Diode and transistor
The diode is the device received by the n-connection and p-semiconductors. He played a huge role in development of a radar-location in 40 years of the last century. The team of staff of the American firm Bell led by U.B. Shokkley actively was engaged in studying its opportunities. These people inventedof transistor in 1948, having attached to a crystal Germany two contacts. On the ends of a crystal there were tiny copper edges. Possibilities of such device made the real revolution in electronics. It was found out that the current passing through the second contact can be operated (to strengthen or weaken it) by means of entrance current of the first contact. It was possible provided that a crystal Germany is much thinner, than copper edges. The first transistors had an imperfect design and quite weak characteristics. Despite this, they were much better than electron tubes. For this invention of Shokkley and his team received the Nobel Prize. In 1955 there were diffusive transistors which surpassed in the characteristics germanic several times.