Cadmium Sulfide (CdS) Nanoparticles
Cadmium Sulfide (CdS) nanoparticles are usually found in a vibrant yellow powder form. CdS can have two different crystal structures; cubic and hexagonal. The hexagonal structure is found to be more stable than the cubic structure, however; they are both available in nature. In addition to these structures, a high-pressure rocksalt phase is only available in nanoscale structures of CdS. It has a relatively high melting point of 1750°C. The solubility of CdS in water is negligible while it is soluble in acidic solutions. CdS is a well-known semiconductor with Eg ≈ 2.5 eV. It is used in photodetectors and for solar cell applications as n-type window layers in heterojunction devices. CdS nanoparticles are attractive candidates for optoelectronic applications as it is possible to engineer the bandgap over a wide spectral range (visible to UV). Another application area of CdS nanoparticles is as a photosensitizer in different matrices such as silica, polymer, and carbon nanotubes.