InterviewSolution
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InterviewSolution
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Classify each of the following as either a p – type or a n – type semiconductor.(1) Ge doped with In(2) Si doped with B. |
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Answer» Both (1) and (2) come under "p – type semiconductors". Reason : In both the cases dopants (i.e.,) Indium in case – (1) and Boron in case – (2) belong to III (or) 13th group. Si (or) Ge doped with III group element is known as p-type semi conductor. Explanation : Doping the silicon or germanium element with III or 13th group element like "B", Al, Ga or "In" results in the substitution of some silicon atoms in its structure by the dopant. The dopant has only three valency electrons. The fourth valency electron is required. It is left as a vacant place on the atom. It is known as an 'electron vacancy' (or) a 'hole'. The electron vacancy on an atom in the structure migrates from one atom to another. Hence it facilitates the electrical conductivity. Si (or) Ge, doped with elements that create a hole in the structure, is known as p-type semi-conductor. |
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