Cadmium Telluride

Definition

Cadmium telluride (CdTe) is a semiconductor material made up of cadmium and tellurium, commonly used in thin-film solar cells due to its favorable electronic properties. Its unique bandgap of approximately 1.5 eV makes it ideal for converting sunlight into electricity, providing an efficient and cost-effective option for solar energy applications.

5 Must Know Facts For Your Next Test

1. Cadmium telluride is recognized for its high absorption coefficient, meaning it can absorb a large amount of sunlight with a thin layer, reducing material costs.
2. It is often paired with a transparent conductive oxide layer to enhance the efficiency of the solar cell by allowing light to pass through while collecting electricity.
3. CdTe solar cells have achieved efficiencies exceeding 22% in laboratory conditions, making them one of the most efficient thin-film technologies available.
4. The production of cadmium telluride involves processes like chemical vapor deposition or close-spaced sublimation, which are essential for creating high-quality films.
5. Environmental concerns arise due to the toxicity of cadmium; however, the industry is working on recycling technologies to minimize waste and ensure safety.

Review Questions

• How does the bandgap of cadmium telluride influence its performance in solar cells?
  • The bandgap of cadmium telluride, which is around 1.5 eV, plays a crucial role in its performance as a solar cell material. This specific bandgap matches well with the solar spectrum, allowing it to efficiently convert sunlight into electricity. The material's ability to absorb photons and generate electron-hole pairs makes it an effective semiconductor for capturing solar energy, contributing significantly to the overall efficiency of CdTe solar cells.
• Discuss the manufacturing processes involved in producing cadmium telluride solar cells and their significance for efficiency.
  • Manufacturing cadmium telluride solar cells typically involves techniques like chemical vapor deposition and close-spaced sublimation. These processes are significant because they allow for the creation of high-quality thin films with optimal thickness and uniformity. By controlling these parameters during production, manufacturers can enhance the efficiency of the solar cells, resulting in better energy conversion rates and lower production costs.
• Evaluate the environmental implications of using cadmium telluride in solar technology and potential solutions for addressing these concerns.
  • Using cadmium telluride in solar technology raises important environmental concerns due to the toxicity of cadmium. However, advancements in recycling technologies offer potential solutions to mitigate these risks. Implementing systems that safely recycle CdTe materials can reduce waste and limit environmental exposure. Additionally, ongoing research aims to develop safer alternatives or improve the lifecycle management of cadmium-containing products, ensuring that the benefits of renewable energy are realized while addressing environmental safety.

Related terms

Thin-Film Solar Cells: Solar cells that are made by depositing one or more thin layers of photovoltaic material, such as cadmium telluride, onto a substrate to create a lightweight and flexible solar panel.

Photovoltaic Effect: The process by which a material generates electric current when exposed to light, fundamental to the operation of solar cells.

Semiconductor: A class of materials that have electrical conductivity between that of conductors and insulators, widely used in electronic devices and solar technologies.