Characterization Effort of HgI2 Radiation Detectors by Pulsed Laser Transient Charge Injection Technique

Both space-charge-limited current and space-charge-free current pulses for electron and hole injection in HgI2 crystals have been observed using the Pulsed Laser Transient Charge Technique. A semi-quantitative theoretical analysis is made based on the assumption of a semi-insulating material. The current pulse analysis includes trapping, detrapping, field dependent trapping times (in both space charge free and limited cases), and plasma dispersal times. Measurement of trapping times and mobilities for both types of carriers are made from the pulse shapes. Measured values for the mobilities of both electrons and holes and trapping times are comparable to previous measurements using different techniques. The experimental techniques are also described. Lastly, the crystal growing techniques are outlined.