Cadmium Telluride (CdTe): A Comprehensive Review on Properties, Thin-Film Fabrication, and Applications

Cadmium telluride (CdTe) is a II–VI compound semiconductor that has attracted significant scientific and technological interest due to its favorable optoelectronic properties, particularly its direct band gap, high absorption coefficient, and excellent electronic characteristics. CdTe possesses a direct band gap of approximately 1.45 eV at room temperature, which is close to the optimal band gap for solar energy conversion according to the Shockley–Queisser limit. This makes CdTe one of the most promising absorber materials for thin-film photovoltaic applications. Moreover, CdTe exhibits a very high absorption coefficient (greater than 105 cm−1) in the visible spectral region, enabling the absorption of most incident solar radiation within a few micrometers of material thickness. These intrinsic properties allow the fabrication of efficient and cost-effective thin-film devices using relatively small amounts of material compared to conventional crystalline silicon technologies. Cadmium telluride (CdTe) is a II–VI compound semiconductor that has attracted significant attention due to its direct band gap, high absorption coefficient, and excellent optoelectronic properties. CdTe has been widely used in photovoltaic devices, photodetectors, radiation detectors, and other electronic and optoelectronic applications. This review article provides a comprehensive overview of CdTe, including its crystal structure, physical and chemical properties, fabrication techniques, device applications, challenges, and future research directions.