Electrical properties of intrinsic p-type shallow levels in HgCdTe grown by molecular-beam epitaxy in the (111)B orientation

The electrical properties of the unintentionally doped p-type HgCdTe material as grown in the (111)B orientation by molecular-beam epitaxy are revised. The analysis of the Hall coefficient in the whole temperature range with a model based on the two-band nonparabolic Kane model, a fully ionized compensating donor concentration, and two independent discrete acceptor levels is presented. The donor compensation is found to be much lower than before, in agreement with the latest study of extrinsic doping by indium. A defect level with an energy of 30 to 50 meV is found necessary to explain properly some of the crystals' data. The results of a three-carrier band modeling of the Hall constant versus field are also presented for one sample and are in very good agreement with the expected band structure of the material. These results show that important improvements have been made recently in the control of stoichiometry during growth