Metastable Pb1−xCdxS epitaxial films. III. Optical properties

The optical properties of metastable epitaxial films of Pb1−xCdxS on NaCl were measured at room temperature for 0⩽x⩽0.38. The refractive index, high‐frequency dielectric constant, susceptibility effective mass, and band gap were measured over this range. It was found that the fundamental absorption edge Eg(Pb1−xCdxS) could be written as Eg(Pb1−xCdxS) =Eg(PbS)+1.80x.