Germanium or silicon becomes extrinsic semi conductor due to

Options

A. Schottky defect
B. Chemicals
C. Frenkel defect
D. Both 1 and 2

Explanation

To answer the question of why Germanium or Silicon becomes an extrinsic semiconductor, we can break down the explanation into clear steps:

### Step-by-Step Solution:

1. **Understanding Semiconductors**:
- Semiconductors are materials that have electrical conductivity between that of conductors and insulators. They can conduct electricity under certain conditions.

2. **Intrinsic vs. Extrinsic Semiconductors**:
- **Intrinsic Semiconductors**: Pure semiconductors without any significant impurities. Their conductivity is due to the electrons and holes generated within the material.
- **Extrinsic Semiconductors**: These are semiconductors that have been doped with impurities to enhance their conductivity.

3. **Doping Process**:
- The process of adding impurities to a semiconductor is called doping. This is what transforms intrinsic semiconductors (like pure Germanium or Silicon) into extrinsic semiconductors.

4. **Types of Doping**:
- There are two main types of doping:
- **N-type Doping**: Involves adding pentavalent impurities (elements from group 15 of the periodic table, such as Phosphorus). This adds extra electrons to the semiconductor.
- **P-type Doping**: Involves adding trivalent impurities (elements from group 13 of the periodic table, such as Boron). This creates holes (positive charge carriers) in the semiconductor.

5. **Conclusion**:
- Germanium and Silicon become extrinsic semiconductors due to the addition of impurities (chemicals) that either donate extra electrons (for N-type) or create holes (for P-type). This significantly increases their electrical conductivity.

### Final Answer:
Germanium or Silicon becomes an extrinsic semiconductor due to the addition of impurities (chemicals) that enhance their conductivity.

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