Intrinsic semiconductor is converted into ntype extrinsic semiconductor by doping it with

Options

A. phosphorous
B. aluminium
C. silver
D. germanium

Answer

To convert an intrinsic semiconductor into an n-type extrinsic semiconductor, we need to dope it with a suitable material. Here’s a step-by-step solution to the question:

### Step 1: Understand the Types of Semiconductors
- **Intrinsic Semiconductor**: This is a pure semiconductor with no impurities. It has equal numbers of electrons and holes.
- **Extrinsic Semiconductor**: This is a semiconductor that has been doped with impurities to change its electrical properties.

### Step 2: Identify the Type of Doping Required
- **N-type Semiconductor**: In this type, the majority charge carriers are electrons. To achieve this, we need to introduce extra electrons into the semiconductor.

### Step 3: Choose the Right Doping Material
- To create an n-type semiconductor, we need to use a **pentavalent** atom (an atom with five valence electrons). This is because when a pentavalent atom is added to the semiconductor, it donates an extra electron, which becomes a free charge carrier.

### Step 4: Analyze the Given Options
- **Phosphorus**: This is a pentavalent atom (5 valence electrons).
- **Aluminum**: This is a trivalent atom (3 valence electrons).
- **Germanium**: This is a pure semiconductor and does not contribute extra electrons.
- **Silver**: This is not typically used for doping semiconductors.

### Step 5: Conclusion
Since we need a pentavalent atom to create an n-type semiconductor, the correct answer is **Phosphorus**.

### Final Answer
The intrinsic semiconductor is converted into an n-type extrinsic semiconductor by doping it with **Phosphorus**.

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