Question

Which kind of defects are introduced by doping?
$A.$ Dislocation defects
$B.$ Schottky defects
$C.$Electronic defects
$D.$ Frenkel defects

Answer 1

Hint – In this question by looking at the meaning of doping and then by looking at the defects of doping, we will get our answer.

Complete step-by-step answer:
Doping is the process of adding impurities to intrinsic semiconductors to alter their properties.
Trivalent and Pentavalent elements are used to dope silicon and germanium. When an intrinsic semiconductor is doped with trivalent impurity it becomes a p-type semiconductor.
When we dope intrinsic material with pentavalent impurities we get n- type semiconductor.
When an electron$\left( {{e^ - }} \right)$ deficit species or electron$\left( {{e^ - }} \right)$rich species is added to a perfect crystal then it results in doping.
Doping is done with electron rich or electron deficient impurities. Hence, it results in a defect caused by an electron which is called an electronic defect.
Electronic defects are called the Thermodynamic defects as the number of these defects depends on temperature. Generally, electrons are present in fully occupied lowest energy states. But at high temperatures, some of the electrons may occupy higher energy states depending upon the temperature. This type of conduction is known as intrinsic conduction. The electron deficient bond formed by the release of an electron is called a hole. In the presence of an electric field the positive holes move in a direction opposite to that of the electrons and conduct electricity. The electrons and holes in the solids give rise to electronic defects.

Note – Whenever we come up with this type of question, one must know that Doping is done in semiconductors in order to increase their conductivity, as normally they have very little conductivity because the band gap between valence and conduction band is large. Extrinsic semiconductors are formed as a result of doping.