Effects of Contact Materials on the Thermally Stimulated Current Spectra of Mercuric Iodide

Mercuric iodide (HgI2) single crystals deposited with transparent indium-tin-oxide (ITO), and semitransparent gold and nickel contacts were investigated by thermally stimulated current spectroscopy (TSC). The differences in the TSC spectra from these samples indicate that the defect structure in HgI2 may be modified by the contact material. These defects act as carrier traps and have strong implications in the application of HgI2 nuclear detectors. A method of numerical analysis was developed to extract information such as carrier trap activation energy, capture cross-section, and trap concentration-lifetime product from the TSC measurements.