Simulation of CdTe:Ge crystal properties for nuclear radiation detectors

We report on the electrical simulation results for the coplanar detector made from a Ge-doped CdTe crystal. The simulations have been performed using the commercial modeling package MEDICI. The detailed models of material behavior have been created by changing the concentration of three standard traps associated with CdTe:Ge material. These traps are the A-center, a vacancy defect related to Te and the Ge impurity. Their energetic positions were measured by photoluminescence technique. The simulation has revealed the effects of the traps on several detector characteristics, in particular the leakage current and electric field distribution.