Theory for electron mobilities in n‐type Hg1−xCdxTe and CdTe at low temperatures

Kohler’s variational method is employed to calculate electron mobilities for n‐type Hg1−xCdxTe and CdTe. Scattering mechanisms considered include ionized and neutral impurity scattering, acoustic, piezoelectric, and optical phonon scattering, and disorder scattering. Ionized impurity cross‐sections are derived from the partial wave phase shift method, since use of the Born approximation can lead to significant error. Because the absence of carrier freeze‐out prevents an independent determination of compensation densities for Hg1−xCdxTe , a direct comparison with experiment is possible only for CdTe. In that case the agreement is relatively good down to about 30 K, but the theoretical values of mobility are greater than the measured values at the lowest temperatures. Similar behavior has already been observed in other semiconductors, and is probably due at least in part to the effects of multi‐ion scattering. The application of the phase shift method to p‐type Hg1−xCdxTe is also briefly considered. Criteri...