CADMIUM TELLURIDE (Syllabus: GS Paper 3 – Sci and Tech)

Context: A study by researchers at the Indian Institute of Technology (IIT), Mandi, reveals that CdTe (Cadmium Telluride) technology has one of the lowest environmental impacts among solar cell technologies in India.

Cadmium Telluride

• About: It is a material made from the combination of two elements: Cadmium (Cd) and Tellurium (Te).
• Physical Properties: It is an odorless and black crystalline solid.
• Properties
• Solubility: It is insoluble in water but resolves in nitrate acid, with resulting oxidation in moisture air under long-term exposure.
• Environmental Impact: It has the lowest carbon dioxide emissions, ozone depletion potential, human health effects, and particulate air pollution.
• Applications

o Semiconductor Detectors: It is considered a prospective material for room temperature semiconductor detector applications such as infrared optical windows and lenses.

o Solar Cells: CdTe is the second most common Photo Voltaic (PV) technology in the world, after silicon.

• Sustainability Assessment: It was one of five solar cell technologies on which IIT scientists conducted a life-cycle assessment (LCA) to identify the most sustainable options for solar energy production in India. 

o The other four were mono-silicon, polysilicon, Copper Indium Gallium Selenide (CIGS), and Passivated Emitter & Rear Contact (PERC).

• Comparison: CdTe was closely followed by CIGS (Copper Indium Gallium Selenide) PV cells in terms of sustainability and performance.