What is p-type semiconductor

These are obtained by adding a small amount of trivalent impurity to a pure sample of semiconductor (Ge).

Majority charge carriers — holes

Minority charge carriers — electrons

• 1. • Conductivity σ » n_h µ_h e
     • P-type semiconductor is also electrically neutral (not positively charged).
     • Impurity is called Acceptor impurity.
     • Acceptor energy level lies just above the valence band.

Conductivity of Semiconductor

(1) In intrinsic semiconductors ne = n_h.

(2) When some potential difference is applied across a piece of intrinsic semiconductor current flows in

it due to both electron and holes.

i= i_e+i_h Þ i =eA[n_ev_e+n_hv_h]