Investigation of Deep Level Defects in Mercuric Iodide by Thermally Stimulated Current Spectroscopy

ABSTRACTMercuric iodide (HgI2) single crystals deposited with semitransparent Pd, Al and Ag contacts were studied by thermally stimulated current spectroscopy (TSC). Distinct differences were found among spectra obtained friom samples withdifferentmetal contacts, indicating that interactions between the metal contacts and mercuric iodide substrates have strong effects on the deep defect levels in mercuric iodide. The activation energies of some of these defect levels were estimated bytaking TSC spectra with different heating rates. In addition, a pyroelectric effect was observed in Ag-contactedsamplesbythermally stimulated depolarization current technique (TSDC). The implications of these results in device applicationsof mercuric iodide are discussed.