Question

Match List I with List II:

List I		List II
A	Intrinsic Semiconductor	I	Fermi-level near the conduction band
B	n-type semiconductor	II	Fermi-level in the middle of valence and conduction band
C	p-type semiconductor	III	Fermi-level near the valence band
D	Metals	IV	Fermi-level inside the conduction band

Choose the correct answer from the options given below:

• A. A-I, B-II, C-III, D-IV
• B. A-III, B-I, C-II, D-IV
• C. A-II, B-I, C-III, D-IV
• D. A-II, B-III, C-I, D-IV

Answer 1

The Correct Option is D

To correctly match List I with List II, we need to understand the position of the Fermi level in different types of semiconductor materials and metals:

1. Intrinsic Semiconductor: In intrinsic semiconductors, the Fermi level is located in the middle of the valence and conduction bands. This is because there is an equal probability of electrons and holes being present, indicating no preference for conducting electron or hole carriers. Thus, Intrinsic Semiconductor matches with II. Fermi-level in the middle of valence and conduction band.
2. n-type Semiconductor: Doping a semiconductor with donor atoms increases electron concentration, pushing the Fermi level closer to the conduction band to account for the increased electron presence. Therefore, n-type Semiconductor should match with III. Fermi-level near the conduction band.
3. p-type Semiconductor: Conversely, p-type semiconductors are doped to increase hole concentration. This results in the Fermi level moving closer to the valence band. Hence, p-type Semiconductor corresponds with I. Fermi-level near the valence band.
4. Metals: For metals, the Fermi level usually lies within the conduction band itself due to the high density of conduction electrons. As a result, Metals go with IV. Fermi-level inside the conduction band.

Based on these understandings, the correct matching from the options given would be:

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

Option: A-II, B-III, C-I, D-IV