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Which of these semiconductor types contain pentavalent elements as impurities?

  1. intrinsic
  2. n-type extrinsic
  3. p-type extrinsic
  4. none of the above

Answer (Detailed Solution Below)

Option 2 : n-type extrinsic
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Detailed Solution

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  • A pentavalent element has 5 valence electrons some examples are arsenic and phosphorous. These elements belong to Group 5.
  • An N-type extrinsic semiconductor has pentavalent impurities.
  • Since there is 1 extra valence electron in the pentavalent elements (5 valence electrons), the majority charge carriers in n-type semiconductor are electron. [4 valence electrons get bonded with surrounding Silicon atom]
  • p-type extrinsic semiconductors have impurities of elements from the Group 3 and holes are the majority charge carriers.
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