What type of semiconductor results when highly purified silicon is doped with arsenic?

Options

A. p-type
B. n-type
C. n,p-type
D. intrinsic

Explanation

To determine the type of semiconductor that results when highly purified silicon is doped with arsenic, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Group of Silicon**:
- Silicon (Si) is a group 14 element in the periodic table.
- It has four valence electrons in its outer shell.

2. **Identify the Group of Arsenic**:
- Arsenic (As) is a group 15 element in the periodic table.
- It has five valence electrons in its outer shell.

3. **Understand Doping**:
- Doping is the process of adding impurities to a semiconductor to change its electrical properties.
- When silicon is doped with arsenic, the arsenic atoms will replace some of the silicon atoms in the crystal lattice.

4. **Analyze the Electron Contribution**:
- Silicon can form four bonds with its four valence electrons.
- When arsenic is introduced, it can form bonds with four of its five valence electrons, leaving one extra electron that does not participate in bonding.

5. **Determine the Type of Semiconductor**:
- The extra electron from the arsenic contributes to the conduction of electricity, making the semiconductor negatively charged.
- This type of semiconductor, which has an excess of electrons, is known as an **n-type semiconductor**.

6. **Conclusion**:
- Therefore, when highly purified silicon is doped with arsenic, the result is an **n-type semiconductor**.

### Final Answer:
The type of semiconductor that results when highly purified silicon is doped with arsenic is an **n-type semiconductor**.