In an semiconductor the separation between conduction band and valence band is of the order of

Options

A. 100 eV
B. 10 eV
C. 1 eV
D. zero

Answer

To determine the separation between the conduction band and the valence band in a semiconductor, we can follow these steps:

### Step-by-Step Solution

1. **Understanding Band Theory**: In solid-state physics, materials are classified based on their electronic band structure. The two important bands are the conduction band (CB) and the valence band (VB).

2. **Conduction Band and Valence Band**:
- The **valence band** is the highest range of electron energies in which electrons are normally present at absolute zero temperature.
- The **conduction band** is the range of electron energies higher than the valence band, where electrons can move freely and contribute to electrical conduction.

3. **Band Gap in Different Materials**:
- In **conductors**, the conduction band and valence band overlap, meaning there is no energy gap (0 eV).
- In **insulators**, the gap is large, typically greater than 1 eV, making it difficult for electrons to jump from the valence band to the conduction band.
- In **semiconductors**, the gap is smaller, allowing some electrons to jump from the valence band to the conduction band under certain conditions (like temperature increase or doping).

4. **Typical Band Gap in Semiconductors**:
- The energy separation (band gap) between the conduction band and valence band in semiconductors is typically around 1 eV. This value allows for some thermal excitation of electrons from the valence band to the conduction band.

5. **Conclusion**: Therefore, the separation between the conduction band and the valence band in a semiconductor is approximately **1 eV**.

### Final Answer
The separation between the conduction band and the valence band in a semiconductor is of the order of **1 eV**.

---