When a junction diode is reverse biased, then current called drift current is due to

Options

A. diffusion of charge
B. nature of the material
C. drift of the charges
D. both drift and diffusion of the charges

Answer

To solve the question regarding the drift current in a reverse-biased junction diode, we will follow these steps:

### Step-by-Step Solution:

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

**Hint**: Recall the basic structure of a p-n junction diode and the types of charge carriers present in each region.

2. **Reverse Bias Condition**:
- When the diode is reverse biased, the positive terminal of the battery is connected to the n-type material, and the negative terminal is connected to the p-type material. This setup increases the width of the depletion region.

**Hint**: Visualize the connection of the battery to understand how it affects the charge carriers in the diode.

3. **Effect on Charge Carriers**:
- In reverse bias, the majority carriers (electrons in n-type and holes in p-type) are pulled away from the junction, widening the depletion region. However, there are still minority carriers present (holes in n-type and electrons in p-type).

**Hint**: Think about what happens to the majority and minority carriers when the diode is reverse biased.

4. **Drift Current**:
- The current that flows due to the movement of these minority carriers across the depletion region is called the drift current. This current is very small compared to the forward bias current.

**Hint**: Focus on the role of minority carriers in generating the drift current.

5. **Conclusion**:
- The drift current in a reverse-biased junction diode is primarily due to the drift of minority charge carriers. Therefore, the correct answer to the question is that the drift current is due to the drift of the charges.

**Hint**: Review the options given in the question and identify which one correctly describes the cause of the drift current.

### Final Answer:
The drift current in a reverse-biased junction diode is due to the drift of the minority charge carriers.