a1 Savannah River National Laboratory, Aiken, South Carolina 29808
a2 Fisk University, Nashville, Tennessee 37208
a3 Lawrence Livermore National Laboratory, Livermore, California 94550
a4 National Institute of Standards and Technology, Gaithersburg, Maryland 20899
a5 University of Chicago—Consortium for Advanced Radiation Sources (CARS), National Synchrotron Light Source, Brookhaven National Laboratory, Upton, New York 11973
Synthetic Cd1–x Zn x Te or “CZT” crystals are highly suitable for γ-spectrometers operating at room temperature. Secondary phases (SP) within CZT, presumed to be Te metal, have detrimental impacts on the charge collection efficiency of fabricated device. Using analytical techniques rather than arbitrary theoretical definitions, we identify two SP morphologies: (i) many void, 20-μm “negative” crystals with 65-nm nanoparticle residues of Si, Cd, Zn, and Te and (ii) 20-μm hexagonal-shaped bodies, which are composites of metallic Te layers with cores of amorphous and polycrystalline CZT material that surround the voids.
(Received June 04 2008)
(Accepted November 19 2008)