Arsenic is used to dope germanium to obtain

Options

A. intrinsic semiconductor
B. p-type semiconductors
C. n-type semiconductors
D. non-conducting germanium

Answer

To solve the question regarding the use of arsenic to dope germanium, we will break down the concepts step by step.

### Step 1: Understanding the Elements
- **Germanium (Ge)** is a member of the carbon family (Group 14) in the periodic table. It has an atomic number of 32 and an electronic configuration of [Ar] 3d10 4s2 4p2.
- **Valence Electrons in Germanium**: Germanium has 4 valence electrons (2 from the 4s subshell and 2 from the 4p subshell).

### Step 2: Understanding Arsenic
- **Arsenic (As)** is a member of the nitrogen family (Group 15) in the periodic table. It has an atomic number of 33 and an electronic configuration of [Ar] 3d10 4s2 4p3.
- **Valence Electrons in Arsenic**: Arsenic has 5 valence electrons (2 from the 4s subshell and 3 from the 4p subshell).

### Step 3: Doping Process
- When arsenic is used to dope germanium, it introduces extra electrons into the germanium crystal lattice.
- The 5 valence electrons from arsenic will interact with the 4 valence electrons from germanium.

### Step 4: Formation of N-type Semiconductor
- In this doping process, 4 of the 5 valence electrons from arsenic will bond with the germanium atoms. However, 1 electron remains unbonded, which becomes a free electron.
- This free electron contributes to electrical conductivity, making the doped germanium an **n-type semiconductor**.

### Conclusion
- Therefore, arsenic is used to dope germanium to obtain **n-type semiconductors** due to the presence of the free electron that enhances conductivity.

### Final Answer
Arsenic is used to dope germanium to obtain **n-type semiconductors**.

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