Using photoluminescence (PL) and current deep-level transient spectroscopy (I-DLTS), we investigated the electronic defects of indium-doped detector-grade CdMnTe:In (CMT:In) crystals grown by the vertical Bridgman method. We similarly analyzed CdZnTe:In (CZT:In) and undoped CdMnTe (CMT) crystals grown under the amount of same level of excess Te and/or indium doping level to detail the fundamental properties of the electronic defect structure more readily. Extended defects, existing in all the samples, were revealed by synchrotron white beam x-ray diffraction topography and scanning electron microscopy. The electronic structure of CMT is very similar to that of CZT, with shallow traps, A-centers, Cd vacancies, deep levels, and Te antisites. The 1.1-eV deep level, revealed by PL in earlier studies of CZT and CdTe, were attributed to dislocation-induced defects. In our I-DLTS measurements, the 1.1-eV traps showed different activation energies with applied bias voltage and an exponential dependence on the trap-filling time, which are typical characteristics of dislocation-induced defects. We propose a new defect-trap model for indium-doped CMT crystals.
We evaluated the long-term stability of CdMnTe (CMT) detectors treated with ammonium-saltbased passivants. Passivation improved the detector's stability and reduced the degradation of its energy resolution with time. Here, we stored passivated 5 × 5 × 9 mm 3 CMT detectors in an ambient environment for 550 days and evaluated the effects of aging by measuring their pulse-height spectra over time. The CMT detector passivated with ammonium fluoride exhibited a higher leakage current after 550 days, and its performance was degraded accordingly. Our analyses of the leakage current for a pixelated CMT detector revealed that the edges and the corners of the detector were responsible for the higher leakage, which resulted from a degradation of the passivation layer in those areas. Assurance of the long-term stability and reproducibility of the detector necessitates that the edges and the corners be mechanically passivated following chemical treatment.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.