Point Defects in Pb-, Bi-, and In-Doped CdZnTe Detectors: Deep-Level Transient Spectroscopy (DLTS) Measurements
2012
Abstract
We studied, by current deep-level transient spectroscopy (I-DLTS), point defects induced in CdZnTe detectors by three dopants: Pb, Bi, and In. Pb-doped CdZnTe detectors have a new acceptor trap at around 0.48 eV.
The absence of a V-Cd trap suggests that all Cd vacancies are compensated by Pb interstitials after they form a deep-acceptor complex [[Pb-Cd](+)-V (Cd) (2-) ](-). Bi-doped CdZnTe detectors had two distinct traps: a shallow trap at around 36 meV and a deep donor trap at around 0.82 eV.
In detectors doped with In, we noted three well-known traps: two acceptor levels at around 0.18 eV (A-centers) and 0.31 eV (V-Cd), and a deep trap at around 1.1 eV.