Electro-migration of ionized/electrically active impurities in CdZnTe (CZT) was successfully demonstrated at elevated temperature with an electric field of 20 V/mm. Copper, which exists in positively charged states, electro-migrated at a speed of 15 μm/h in an electric field of 20 V/mm. A notable variation in impurity concentration along the growth direction with the segregation tendency of the impurities was observed in an electro-migrated CZT boule. Notably, both Ga and Fe, which exist in positively charged states, exhibited the opposite distribution to that of their segregation tendency in Cd(Zn)Te. A CZT detector fabricated from the middle portion of the electro-migrated CZT boule showed an improved mobility-lifetime product of 0.91 × 10−2 cm2/V, compared with that of 1.4 × 10−3 cm2/V, observed in an as-grown (non-electro-migrated) CZT detector. The optimum radiation detector material would have minimum concentration of deep traps required for compensation.

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The availability of large volume crystals with the same energy gap in melt-grown CdZnTe(CZT)is restricted due to the Zn segregation in CdTe hosts. We observed the migration of Zn in the solid phase along the positive temperature gradient direction both in-situ and post-growth temperature gradient annealing (TGA) of CZT. Diffusivity of Zn obtained from the in-situ TGA was approximately 10 −5 (cm 2 /s) order and completely different mechanism with that of post-growth. The CZT ingots obtained through in-situ TGA have uniform Zn and resistivity of 10 10 Ω•cm orders. The CZT detectors fabricated from in-situ TGA applied ingots exhibit 10 % of energy resolution for 59.5 keV peak of 241 Am.

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