Which of the following statement is true

Options

A. Doping of pure Ge with a trivalent impurity gives n-type semiconductor
B. Resistivity of pure Ge increases with temperature
C. Majority Carriers in p type semiconductor are holes
D. Doping of pure Ge with a pentavalent impurity increases its resistivity

Explanation

To determine which statement is true regarding semiconductors, let's analyze each statement step by step:

### Step 1: Understand Doping
Doping refers to the process of adding impurities to a pure semiconductor material (like germanium) to change its electrical properties. There are two types of dopants:
- **Trivalent Impurities** (e.g., Boron) - These have three valence electrons and create "holes" in the semiconductor, resulting in a **p-type** semiconductor.
- **Pentavalent Impurities** (e.g., Arsenic) - These have five valence electrons and provide extra electrons, resulting in an **n-type** semiconductor.

### Step 2: Analyze Each Statement
1. **Doping of pure germanium with a trivalent impurity gives n-type semiconductor.**
- This statement is **false**. Doping with a trivalent impurity creates a p-type semiconductor, not n-type.

2. **Resistivity of pure germanium increases with temperature.**
- This statement is **false**. In semiconductors, as temperature increases, the resistivity generally decreases because more charge carriers (electrons and holes) are generated.

3. **Majority carrier in p-type semiconductor.**
- This statement is **true**. In a p-type semiconductor, the majority carriers are holes, which are created by the absence of electrons.

4. **Doping of pure germanium with a pentavalent impurity increases its resistivity.**
- This statement is **false**. Doping with a pentavalent impurity actually decreases the resistivity because it adds more free electrons.

### Conclusion
The true statement is: **C. Majority carrier in p-type semiconductor are holes.**

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