Magneto‐optical spectra of donor impurities in Hg_0.7Cd_0.3Te

We report the observation of shallow donor transitions in Hg0.7 Cd0.3 Te by far‐infrared magnetoabsorption and magnetophotoconductivity. The transitions observed are impurity‐shifted cyclotron resonance in the Faraday geometry and the (000)–(001) transition in the Voigt geometry. Magnetophotoconductivity spectra of the (000)–(001) transition showed structure which may be due to central cell effects of impurities. We also studied the magnetic field dependence of the transition energies and found good agreement with theory for the (000)–(001) transition.