Q. Explain the compositional defects.
Ans. Compositional Defect: This defect due to
(a) Alloying an element to original crystal.
(b) Impuring atom during original crystallization.
These defects are responsible for functioning of most semiconductor devices.
A substitutional impurity defect is also a point defect in which a foreign atoms that substitutes for a parent atom in the crystal lattice e.g. in bras, zinc is a substitutional atom in the copper.
A interstitial impurity is a small sized atom occupying space between the regularity positioned atoms.