Study of stoichiometry in mercuric iodide by low temperature photoluminescence spectroscopy

Low temperature (4.2 K) photoluminescence spectroscopy (PL) measurements were performed on mercuric iodide (HgI2) crystals that were surface-doped with either iodine or mercury. Two methods of treatment were used to achieve the surface doping. The first is the direct immersion of HgI2 samples into potassium iodide (KI) aqueous solution saturated with iodine or immersion into elemental mercury liquid. The second is the storage of HgI2 crystals under either iodine or mercury vapor. Certain features in the PL spectra were correlated with the stoichiometry of the HgI2/ crystals modified by the surface doping. It was also found that if HgI(subscript 2 was exposed to air, an iodine deficient surface layer would form within a one-day period due to the preferential loss of iodine. Finally, the behavior of a broad emission band in the PL spectra and its implication in the fabrication of high quality HgI2 nuclear detector is discussed.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.