SPATIAL NONUNIFORMITY IN CD-ANNEALED CDTE CRYSTALS

The uncompensated shallow donor concentration (N(D) - N(A)) has been measured in bulk grown, Cd annealed CdTe samples as a function of depth. Although previous work has shown that the annealing conditions (48 h at 800-degrees-C) are sufficient to provide homogeneous properties at the annealing temperature, the room temperature measurements reported here indicate significant non-uniformity, with a peak in (N(D) - N(A)) in the vicinity of 100 mum from the sample surface. Such a depth is shown to be consistent with a characteristic depth over which defects are redistributed during the cooling process.