When NiO is doped with a small quantity of `Li_(2)O`

Options

A. both cation and anion vacancies are generated
B. Schottky defects are generated
C. NiO becomes an n-type semiconductor
D. NiO becomes a p-type semiconductor

Answer

To solve the question regarding the doping of NiO with Li₂O, let's break down the process step by step.

### Step-by-Step Solution:

1. **Understanding the Components**:
- Nickel oxide (NiO) consists of Ni²⁺ ions and O²⁻ ions.
- Lithium oxide (Li₂O) consists of Li⁺ ions and O²⁻ ions.

2. **Doping Process**:
- When a small quantity of Li₂O is added to NiO, the Li⁺ ions will replace some of the Ni²⁺ ions in the lattice structure of NiO.
- Each Ni²⁺ ion can be replaced by two Li⁺ ions to maintain charge neutrality because Li⁺ has a +1 charge and Ni²⁺ has a +2 charge.

3. **Charge Balance**:
- For every Ni²⁺ ion replaced, two Li⁺ ions are introduced. This results in a decrease in the number of Ni²⁺ ions in the lattice.
- The substitution of Ni²⁺ ions by Li⁺ ions leads to a reduction in the number of unpaired electrons in the material.

4. **Type of Semiconductor**:
- A decrease in unpaired electrons indicates that the material behaves as a p-type semiconductor. In p-type semiconductors, there are more holes (absence of electrons) than electrons, which allows for the conduction of electricity.

5. **Conclusion**:
- Therefore, the correct conclusion is that NiO becomes a p-type semiconductor when doped with Li₂O.

### Final Answer:
When NiO is doped with a small quantity of Li₂O, it becomes a p-type semiconductor.