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Distinguish between intrinsic and extrinsic conduction in a semiconductor. - Leaving Cert Physics - Question h - 2020
Question h
Distinguish between intrinsic and extrinsic conduction in a semiconductor.
Worked Solution & Example Answer:Distinguish between intrinsic and extrinsic conduction in a semiconductor. - Leaving Cert Physics - Question h - 2020
Step 1
Intrinsic conduction
Answer
Intrinsic conduction occurs in a pure semiconductor, where conduction is due to the equal number of holes and electrons present. In intrinsic semiconductors, the material is undoped, and the charge carriers are generated by thermal excitation, resulting in a balanced number of electrons in the conduction band and holes in the valence band.
Step 2
Extrinsic conduction
Answer
Extrinsic conduction occurs in a doped semiconductor, where there is an excess of either holes or electrons. This doping process introduces impurities into the semiconductor, which alters its electrical properties. Depending on the type of dopant, either n-type (excess electrons) or p-type (excess holes) conduction will occur, enhancing the material's conductivity significantly.