Detection of dilute iron impurities in CdTe.

CdTe single crystals from several sources have been examined to detect the presence of impurities which may be detrimental to applications in the fabrication of IR detectors. Distinctive electron paramagnetic resonance (EPR) signals from several donor impurities, including substitutional paramagnetic Fe, were found in several samples. A photoluminescence (PL) transition at 1.1 eV was also seen in these crystals and the amplitudes of the PL signals and the Fe EPR signals are strongly correlated. Elemental analysis of the samples indicates that EPR and PL are able to detect Fe concentrations of less than 0.1 ppm. [ABSTRACT FROM AUTHOR]