Luminescence properties of CZT crystals in the presence of tellurium inclusions

A 3D IR-mapping instrument has been developed at IMEM for the detection of Te inclusions inside CdZnTe crystals. By means of this apparatus, it is possible to reconstruct the position of each inclusion inside the sample. The use of such a high resolution instrument has been fundamental in this work for the identification of a large Te inclusion (20 μm) located just a few micrometers under the sample surface. Photoluminescence mapping of the region near the inclusion revealed the enhancement of a near mid-gap band emission (0.78 eV) close to the defected region surrounding the inclusion. This supports the evidences of trap-like behaviour of the Te inclusions on the charge collection induced by this localized mid-gap level.