*Question E6F10:
What is the most common material used in power-generating photovoltaic cells?*  

*Correct Answer is  B: Silicon*  

### AI Response: (may contain errors)  

Photovoltaic cells, commonly known as solar cells, convert sunlight into electrical energy. The most common material used in these cells is **silicon**. Here's why:

1. **Why Silicon is Correct:**
   - **Abundance and Cost:** Silicon is the second most abundant element in the Earth's crust, making it relatively inexpensive and widely available.
   - **Efficiency:** Silicon-based solar cells have a good balance of efficiency and cost-effectiveness. They typically achieve efficiencies between 15% and 22%.
   - **Mature Technology:** Silicon technology is well-developed, with a long history of research and development, leading to reliable and durable solar cells.

2. **Why the Other Choices are Incorrect:**
   - **Selenium (A):** Selenium was used in early photovoltaic cells but is less efficient and more expensive compared to silicon. It is not commonly used in modern solar cells.
   - **Cadmium Sulfide (C):** While cadmium sulfide is used in some thin-film solar cells, it is not as common as silicon due to toxicity concerns and lower efficiency.
   - **Indium Arsenide (D):** Indium arsenide is used in specialized applications, such as infrared detectors, but not in standard photovoltaic cells due to its high cost and complexity.

In summary, silicon is the most common material for photovoltaic cells due to its abundance, cost-effectiveness, and efficiency, making it the preferred choice for most solar power applications.