Match List-I with List-II

Choose the correct answer from the options given below:

(A)-(IV), (B)-(I), (C)-(II), (D)-(III)

The correct answer is Option (3) → (A)-(IV), (B)-(I), (C)-(II), (D)-(III)

(A) Intrinsic Semiconductor

An intrinsic semiconductor is a pure semiconductor without any significant dopant species present.

• Logic: Charge carriers are generated solely by thermal excitation, which creates an electron-hole pair. Therefore, the number of conduction electrons ($n_e$) is exactly equal to the number of holes ($n_h$).
• Matches with (IV): Number of conduction electrons = number of holes.

(B) n-type Semiconductor

An n-type semiconductor is created by adding pentavalent impurities (like Phosphorus) to an intrinsic semiconductor.

• Logic: These impurities provide extra electrons to the conduction band. Consequently, electrons become the majority carriers.
• Matches with (I): Number of conduction electrons >> number of holes.

(C) p-type Semiconductor

A p-type semiconductor is created by adding trivalent impurities (like Boron) to an intrinsic semiconductor.

• Logic: These impurities create "holes" (vacancies) in the valence band that can accept electrons. Consequently, holes become the majority carriers.
• Matches with (II): Number of conduction electrons << number of holes.

(D) p-n Junction under Equilibrium

In a p-n junction at equilibrium (with no external voltage applied), a depletion region forms.

• Logic: Diffusion current and drift current oppose each other perfectly. While there is internal movement of charges, there is no external flow of charge through the device.
• Matches with (III): Net current is zero.