Ammonium Fluoride Passivation of CdZnTeSe Sensors for Applications in Nuclear Detection and Medical Imaging
Cadmium zinc telluride selenide (Cd<sub>1−x</sub>Zn<sub>x</sub>Te<sub>1−y</sub>Se<sub>y</sub> or CZTS) is one of the emerging CdTe-based semiconductor materials for detecting X- and gamma-ray radiation at or near room temperature (i...
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MDPI AG
2019-07-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/19/15/3271 |
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| author | Stephen U. Egarievwe Utpal N. Roy Carmella A. Goree Benicia A. Harrison Jeanette Jones Ralph B. James |
| author_facet | Stephen U. Egarievwe Utpal N. Roy Carmella A. Goree Benicia A. Harrison Jeanette Jones Ralph B. James |
| author_sort | Stephen U. Egarievwe |
| collection | DOAJ |
| description | Cadmium zinc telluride selenide (Cd<sub>1−x</sub>Zn<sub>x</sub>Te<sub>1−y</sub>Se<sub>y</sub> or CZTS) is one of the emerging CdTe-based semiconductor materials for detecting X- and gamma-ray radiation at or near room temperature (i.e., without cryogenic cooling). Potential applications of CZTS sensors include medical imaging, X-ray detection, and gamma-ray spectroscopy. Chemical passivation of CZTS is needed to reduce the conductivity of Te-rich surfaces, which reduces the noise and improves the device performance. In this study, we focus on the effect of surface passivation of CZTS using a 10% aqueous solution of ammonium fluoride. The effects of the chemical treatment were studied on the leakage current, charge transport measured as the electron mobility-lifetime (µτ) product, and the spectral resolution measured as the full-width at half-maximum (FWHM) of specific peaks. After passivation, the leakage current increased and began to decrease towards pre-passivation levels. The energy resolutions were recorded for eight applied voltages between −35 V and −200 V. The results showed an average of 25% improvement in the detector’s energy resolution for the 59.6 keV gamma peak of Am-241. The electron µτ product was unchanged at 2 × 10<sup>−3</sup> cm<sup>2</sup>/V. These results show that ammonium fluoride is effective for chemical passivation of CZTS detectors. |
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| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-04-14T05:21:18Z |
| publishDate | 2019-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-2f50a5b3b249461c91b86e56703ebe4d2022-12-22T02:10:10ZengMDPI AGSensors1424-82202019-07-011915327110.3390/s19153271s19153271Ammonium Fluoride Passivation of CdZnTeSe Sensors for Applications in Nuclear Detection and Medical ImagingStephen U. Egarievwe0Utpal N. Roy1Carmella A. Goree2Benicia A. Harrison3Jeanette Jones4Ralph B. James5Nuclear Engineering and Radiological Science Center, Department of Electrical Engineering and Computer Science, Alabama A&M University, Normal, AL 35762, USANational Security and Nonproliferation Department, Brookhaven National Laboratory, Upton, NY 11973, USABiological and Environmental Sciences Department, Alabama A&M University, Normal, AL 35762, USABiological and Environmental Sciences Department, Alabama A&M University, Normal, AL 35762, USABiological and Environmental Sciences Department, Alabama A&M University, Normal, AL 35762, USANational Security and Nonproliferation Department, Brookhaven National Laboratory, Upton, NY 11973, USACadmium zinc telluride selenide (Cd<sub>1−x</sub>Zn<sub>x</sub>Te<sub>1−y</sub>Se<sub>y</sub> or CZTS) is one of the emerging CdTe-based semiconductor materials for detecting X- and gamma-ray radiation at or near room temperature (i.e., without cryogenic cooling). Potential applications of CZTS sensors include medical imaging, X-ray detection, and gamma-ray spectroscopy. Chemical passivation of CZTS is needed to reduce the conductivity of Te-rich surfaces, which reduces the noise and improves the device performance. In this study, we focus on the effect of surface passivation of CZTS using a 10% aqueous solution of ammonium fluoride. The effects of the chemical treatment were studied on the leakage current, charge transport measured as the electron mobility-lifetime (µτ) product, and the spectral resolution measured as the full-width at half-maximum (FWHM) of specific peaks. After passivation, the leakage current increased and began to decrease towards pre-passivation levels. The energy resolutions were recorded for eight applied voltages between −35 V and −200 V. The results showed an average of 25% improvement in the detector’s energy resolution for the 59.6 keV gamma peak of Am-241. The electron µτ product was unchanged at 2 × 10<sup>−3</sup> cm<sup>2</sup>/V. These results show that ammonium fluoride is effective for chemical passivation of CZTS detectors.https://www.mdpi.com/1424-8220/19/15/3271CdZnTeSe detectorschemical passivationgamma-ray detectornuclear radiation detectorX-ray detector |
| spellingShingle | Stephen U. Egarievwe Utpal N. Roy Carmella A. Goree Benicia A. Harrison Jeanette Jones Ralph B. James Ammonium Fluoride Passivation of CdZnTeSe Sensors for Applications in Nuclear Detection and Medical Imaging Sensors CdZnTeSe detectors chemical passivation gamma-ray detector nuclear radiation detector X-ray detector |
| title | Ammonium Fluoride Passivation of CdZnTeSe Sensors for Applications in Nuclear Detection and Medical Imaging |
| title_full | Ammonium Fluoride Passivation of CdZnTeSe Sensors for Applications in Nuclear Detection and Medical Imaging |
| title_fullStr | Ammonium Fluoride Passivation of CdZnTeSe Sensors for Applications in Nuclear Detection and Medical Imaging |
| title_full_unstemmed | Ammonium Fluoride Passivation of CdZnTeSe Sensors for Applications in Nuclear Detection and Medical Imaging |
| title_short | Ammonium Fluoride Passivation of CdZnTeSe Sensors for Applications in Nuclear Detection and Medical Imaging |
| title_sort | ammonium fluoride passivation of cdzntese sensors for applications in nuclear detection and medical imaging |
| topic | CdZnTeSe detectors chemical passivation gamma-ray detector nuclear radiation detector X-ray detector |
| url | https://www.mdpi.com/1424-8220/19/15/3271 |
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