In a forward biased p - n junction diode , which of the following graphs is most appropriately represented the potential barrier in the depletion .region ?

Options

A.
B.
C.
D.

Answer

To solve the question regarding the potential barrier in the depletion region of a forward-biased p-n junction diode, we can follow these steps:

### Step 1: Understand the Structure of a p-n Junction Diode
A p-n junction diode consists of two types of semiconductor materials: p-type (positive) and n-type (negative). The junction between these two materials creates a depletion region where charge carriers (holes and electrons) are depleted.

**Hint:** Remember that the p-type material has an abundance of holes, while the n-type material has an abundance of electrons.

### Step 2: Identify the Characteristics of Forward Bias
In forward bias, the p-type material is connected to the positive terminal of the power supply, and the n-type material is connected to the negative terminal. This reduces the potential barrier at the junction, allowing current to flow.

**Hint:** In forward bias, the potential barrier decreases, making it easier for charge carriers to cross the junction.

### Step 3: Analyze the Potential Barrier in the Depletion Region
In the depletion region, the potential barrier is created due to the difference in concentration of charge carriers. In forward bias, the potential on the n-side is higher than on the p-side, but the overall height of the potential barrier is reduced compared to when the diode is in reverse bias.

**Hint:** Look for a graph that shows a lower potential barrier when the diode is forward biased compared to when it is reverse biased.

### Step 4: Compare the Given Graphs
Among the options provided, we need to identify which graph shows a lower potential barrier at the junction for the forward-biased condition. We can eliminate options that depict a higher potential barrier, which would be indicative of reverse bias.

**Hint:** Focus on the graphs that show a higher potential on the n-side and a lower potential on the p-side, specifically looking for the one with the lowest height of the potential barrier.

### Step 5: Select the Correct Option
After analyzing the graphs, we find that option 4 represents the potential barrier in the depletion region of a forward-biased p-n junction diode correctly. It shows a lower potential barrier compared to the other options, which is consistent with the behavior of a forward-biased diode.

**Final Answer:** The correct option is option 4.