Physics · JEE | Semiconductor Electronics: Materials, Devices and Simple Circuits

Consider the following statements regarding extrinsic semiconductors and doping: (I) Doping is the deliberate addition of a desirable impurity to a pure semiconductor to manifold increase its conductivity. (II) Pentavalent impurities like As, Sb, or P act as donor impurities in tetravalent Si or Ge. (III) In a p-type semiconductor, holes are the majority carriers and the dopant atom acts as an acceptor creating a negative core with an associated hole. (IV) The crystal maintains an overall net negative charge after being doped with trivalent impurities. How many of the above statements are correct?

1. A
   Only two
2. B
   Only three
3. C
   All four
4. D
   Only one