Correct Answer - Option 2 : intrinsic
The correct answer is option 2) i.e. intrinsic
CONCEPT:
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Intrinsic semiconductor: An intrinsic semiconductor is a pure semiconductor without any dopant species present in it.
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Extrinsic semiconductor: An extrinsic semiconductor is one that is doped with impurities of dopant species.
- A p-type semiconductor is a semiconductor doped with atoms with three valence electrons which forms a covalent bond with the semiconductor and leaves behind a hole.
- An n-type semiconductor is a semiconductor doped with atoms with five valence electrons which form four covalent bond with the semiconductor and leaves behind an extra electron.
EXPLANATION:
- An intrinsic semiconductor has electrons in covalent bonds. Hence, at normal temperature and pressure, there is no free charge carrier for conduction.
- So, conduction is possible only if the covalent bond breaks and frees up some electrons.
- As soon as one electron gets free, there is a hole created at the position of the free electron, and the movement of electrons happens within the material.
- Thus, the electrical conductivity of an intrinsic semiconductor is due to the breaking of its covalent bonds.
