question_answer 93)

  Which of the following statements are true about semiconductors? (a) Silicon doped with electron rich impurity is a p -type semiconductor (b) Silicon doped with an electron rich impurity is an n-type semiconductor (c) Delocalised electrons increase the conductivity of doped silicon (d) An electron vacancy increases the conductivity of n-type semiconductor

Answer:

                  (b, c) Silicon doped with an electron rich impurity is an n-type semiconductor. Conductivity of n-type semiconductor is due to presence of free electron delocalisation of electrons increases the conductivity of doped silicon due to increase in mobility of electron.