Trapping effects in silverhyphen;doped mercuric iodide crystals

摘要

Electrical and photoelectrical characteristics of silverhyphen;doped mercuric iodide crystals were investigated with a view to study the trapping phenomena in these crystals. Trapping parameters were determined by thermallyhyphen;stimulatedhyphen;current measurements, photoluminescence spectra, spectral response, and photoconductive decay measurements. The effects of temperature on pulse height under uniform illumination was measured in the temperature range of minus;100 to +100thinsp;deg;C. Resistivity changes andIhyphen;Vcharacteristics are also discussed. Results of the experiments indicate a strong possibility for the existence of at least two main impurity levels in silverhyphen;doped HgI2mdash;one, a hole trapping acceptor level at 0.73 eV above the valence band, and another, possibly a donor level, at 0.26 eV below the conduction band. The effect of a compensated acceptor level on polarization is also shown.