Cadmium telluride

Definition

Cadmium telluride (CdTe) is a compound semiconductor that is widely used in thin-film solar cells due to its favorable electronic properties and efficient light absorption. This material plays a crucial role in the photovoltaic effect by converting sunlight into electricity, making it a significant player in the solar energy industry.

5 Must Know Facts For Your Next Test

1. Cadmium telluride is notable for its high absorption coefficient, which allows it to absorb sunlight effectively even with a thin layer, typically around 1-2 micrometers.
2. The efficiency of CdTe solar cells can reach up to 22%, making them one of the most efficient types of thin-film solar technologies available.
3. CdTe is usually produced through various deposition methods like vapor transport deposition (VTD) and close-spaced sublimation (CSS), which are essential for creating high-quality films.
4. The use of cadmium in CdTe raises environmental concerns, prompting research into recycling and safe disposal methods to mitigate potential risks associated with cadmium toxicity.
5. Cadmium telluride solar cells can be manufactured at lower costs compared to traditional silicon solar cells, making them an attractive option for large-scale solar installations.

Review Questions

• How does cadmium telluride contribute to the photovoltaic effect in solar cell technology?
  • Cadmium telluride contributes to the photovoltaic effect by absorbing sunlight and generating electron-hole pairs within its structure. When light photons strike the CdTe material, they transfer their energy to electrons, exciting them and allowing them to move freely. This movement creates an electric current as the electrons are directed towards electrodes, ultimately converting solar energy into usable electrical energy. The unique properties of CdTe enable efficient conversion and utilization of sunlight, making it a preferred choice for solar cells.
• What are the advantages and challenges associated with using cadmium telluride in thin-film solar cells compared to other materials?
  • Cadmium telluride offers several advantages over other materials used in thin-film solar cells, such as its high absorption efficiency and lower production costs. However, challenges arise due to environmental concerns linked to cadmium's toxicity, requiring stringent regulations during manufacturing and end-of-life management. Moreover, while CdTe achieves competitive efficiencies, it still faces competition from more established technologies like crystalline silicon. Balancing performance, cost-effectiveness, and environmental responsibility is critical for advancing CdTe solar cell technology.
• Evaluate the implications of doping methods on the performance and efficiency of cadmium telluride solar cells.
  • Doping methods significantly influence the performance and efficiency of cadmium telluride solar cells by controlling the electrical properties of the semiconductor. By introducing specific dopants into the CdTe structure, manufacturers can enhance carrier concentration and mobility, ultimately improving the cell's overall efficiency. These adjustments allow for better light absorption and charge separation within the cell. However, optimizing doping levels is crucial; too much or too little doping can lead to defects that hinder performance. Thus, effective doping strategies are essential for maximizing the potential of CdTe in renewable energy applications.

Related terms

Photovoltaic effect: The process by which a material converts light energy directly into electrical energy through the absorption of photons, leading to the generation of charge carriers.

Thin-film solar cells: Solar cells made by depositing very thin layers of photovoltaic materials on a substrate, allowing for flexibility, lightweight designs, and lower production costs.

Doping: The intentional introduction of impurities into a semiconductor material to alter its electrical properties, enhancing its conductivity and performance.