Depietion layer in the p-n junction consists of

Options

A. ions fixed in their position
B. holes
C. ions and holes
D. both electron and holes

Answer

To solve the question regarding the composition of the depletion layer in a p-n junction, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding the p-n Junction**:
- A p-n junction is formed by joining p-type and n-type semiconductors. The p-type semiconductor has an abundance of holes (positive charge carriers), while the n-type semiconductor has an abundance of electrons (negative charge carriers).

2. **Formation of the Depletion Layer**:
- When the p-n junction is formed, electrons from the n-type region diffuse into the p-type region and recombine with holes. Similarly, holes from the p-type region diffuse into the n-type region and recombine with electrons. This recombination leads to the formation of a depletion layer.

3. **Characteristics of the Depletion Layer**:
- The depletion layer is characterized by a lack of free charge carriers (electrons and holes). Instead, it consists of immobile ions that are left behind after the recombination process.
- In the p-type region, the immobile positive ions (from the acceptor atoms) remain, while in the n-type region, the immobile negative ions (from the donor atoms) remain.

4. **Composition of the Depletion Layer**:
- Therefore, the depletion layer consists of fixed positive ions in the p-region and fixed negative ions in the n-region. It does not contain free electrons or holes, which is why it is called a "depletion" layer.

5. **Conclusion**:
- The depletion layer in a p-n junction consists of immobile ions, specifically negative ions from the n-type side and positive ions from the p-type side.

### Final Answer:
The depletion layer in a p-n junction consists of immobile ions (negative ions from the n-type side and positive ions from the p-type side).