CdTebased

CdTe-based materials refer to compounds built from cadmium telluride (CdTe) and are used primarily in two areas: thin-film photovoltaics and radiation detection. In photovoltaics, CdTe serves as the light-absorbing layer in CdTe solar cells, offering strong absorption and a direct bandgap around 1.45 eV, which is near optimal for converting sunlight into electricity.

Most CdTe solar cells employ a CdS window layer to form a heterojunction with CdTe. Common device stacks include a glass or flexible substrate coated with a transparent conductor, then CdS, then CdTe, and a metal back contact. Post-deposition treatments, such as CdCl2 annealing, improve grain size and passivate defects, boosting efficiency and stability. The technology benefits from low material usage and scalable manufacturing processes, including close-spaced sublimation, sputtering, and vapor deposition on large-area substrates. Lab efficiencies for CdTe cells have surpassed 22%, with commercial modules typically in the low- to mid-20s.

Beyond photovoltaics, CdTe and related alloys are used in radiation detectors, often operating at room temperature. Their high density and atomic numbers provide strong stopping power for X- and gamma rays and enable practical detectors for medical imaging, industrial radiography, security screening, and certain scientific instruments. Detector performance depends on crystal quality and proper device engineering.

Safety and environmental concerns surround cadmium-containing materials. Cadmium is toxic, so handling, containment, and end-of-life recycling are important to minimize environmental impact. When properly encapsulated and recycled, CdTe-based devices can offer advantageous life-cycle economics due to durability and relatively low manufacturing costs.