Correlations between mercuric iodide photoluminescence spectra and nuclear detector performance

Abstract Low temperature photoluminescence spectroscopy was performed on a variety of HgI 2 samples and also on graded HgI 2 nuclear detectors. Correlations were found between features in the photoluminescence spectra and a crystal's ability to produce high-quality detectors. The intensity of a broad emission band centered at 6200 A (designated as band 3) is weaker in crystals that yield high-quality detectors. Therefore, the defects responsible for this emission band are undesirable in the fabrication of HgI 2 nuclear detectors. The measurements also revealed that stronger emission in the exciton region (designated as band 1) is associated with crystals which produce high-quality detectors, indicating that a high degree of structural perfection is important for HgI 2 detector applications. These correlations, together with earlier results from studies of processing-induced defects, lead to suggestions regarding improvement of the manufacturing yield of high-quality HgI 2 detectors.