Study on the performance of HgI2 semiconductor detectors

The room temperature semiconductor detector HgI₂ is well known for its high detection efficiency and low leakage current. But the defects created during the growth degrade the performance of HgI₂ detectors. The low crystal rigidity and the surface instability lead to the difficult operation in crystal processing and further more make the detector performance very sensitive to those processing procedures. When measuring the ²⁴¹Am spectrum with planar contact HgI₂ detectors we found that the 60keV peak suffered the variation from multi peaks to single peak and slow improvement of the spectrum peak shape. These multi peaks reveal the relative serious hole trapping sites inside the HgI₂ crystals and the ununiformity of the crystals. Our research provides the results on the ununiformity, the long time stability of HgI₂ detectors and the improvement from the carbon glue contact material.