Photoluminescence investigations of defects introduced during processing of mercuric iodide nuclear detectors

Low-temperature photoluminescence (PL) spectroscopy was performed on a variety of HgI2 samples to determine the effects of chemical etching with KI and HNO3 solutions and the modifications in the PL spectra due to the presence of carbon, chromium and parylene films. These investigations reveal that the processing steps used to manufacture HgI2 nuclear detectors can lead to the incorporation of new defects into the near-surface region of the crystals. Moreover, correlations between the photoluminescence spectra and detector performance show that some of these defects are undesirable for producing high-quality devices. (orig.)