InterviewSolution
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InterviewSolution
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On doping `Ge` with a little of `In or Ga` one getsA. `p`-type semiconductorB. `n`-type semiconductorC. insulatorD. rectifier |
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Answer» Correct Answer - 1 The electrical conductivity of a semiconductor can be greatly increased by doping with impurities. Doping the Ge crystal with`In` or `Ga` (Group `13` element) produces is `p` type semiconductor. Each In or `Ga` atom contributes only three valence electrons to bonding orbitals in the valence band, and therefore a hole localized near each `In` or `Ga` atom. Thermal energy is enough to separate the negatively charge `In` or `Ga` atom form the hole, delocalizing the latter in this case the charge carries are the holes , which are positive and the crystal is doped p-type. |
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