•The barrier controlled trapping model was developed around extended defects.
•Electron mobility and E-field distribution were distorted by space charge depletion region.
•Extended defects act as a recombination-activated region.
•The relationships between extended defects and detector performance were established.
Transient current techniques using alpha particle source were utilized to study the influence of extended defects on the electron drift time and the detector performance of CdZnTe crystals. Different from the case of trapping through isolated point defect, a barrier controlled trapping model was used to explain the mechanism of carrier trapping at the extended defects. The effect of extended defects on the photoconductance was studied by laser beam induced transient current (LBIC) measurement. The results demonstrate that the Schottky-type depletion space charge region is induced at the vicinity of the extended defects, which further distorts the internal electric field distribution and affects the carrier trajectory in CdZnTe crystals. The relationship between the electron drift time and detector performance has been established.
II–VI semiconductor devices; CdZnTe; Barrier controlled trapping; Extended defects
rolled carrier trapping of extended defects in CdZnTe detector