Optical and Electrical Properties of Bismuth Deposits Doped with Tellurium*

The measured infrared reflectance and transmittance of several bismuth deposits doped with tellurium were used to obtain their electrical and optical constants for the 15–70-µm region. The change of these parameters with wavelength yielded values for the static dielectric constants of the deposits and the relaxation times of the carriers in the deposits. Each deposit was characterized by a reflectance minimum that occurred at shorter wavelengths as the concentration of tellurium in the deposits was increased. The wavelengths at which the reflectance minima occurred have been identified with the wavelengths corresponding to the calculated plasma frequencies.