Charge Sharing and Charge Loss in High-Flux Capable Pixelated CdZnTe Detectors
Cadmium zinc telluride (CdZnTe) detectors are known to suffer from polarization effects under high photon flux due to poor hole transport in the crystal material. This has led to the development of a high-flux capable CdZnTe material (HF-CdZnTe). Detectors with the HF-CdZnTe material have shown prom...
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| Format: | Article |
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MDPI AG
2021-05-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/21/9/3260 |
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| author | Kjell A. L. Koch-Mehrin Sarah L. Bugby John E. Lees Matthew C. Veale Matthew D. Wilson |
| author_facet | Kjell A. L. Koch-Mehrin Sarah L. Bugby John E. Lees Matthew C. Veale Matthew D. Wilson |
| author_sort | Kjell A. L. Koch-Mehrin |
| collection | DOAJ |
| description | Cadmium zinc telluride (CdZnTe) detectors are known to suffer from polarization effects under high photon flux due to poor hole transport in the crystal material. This has led to the development of a high-flux capable CdZnTe material (HF-CdZnTe). Detectors with the HF-CdZnTe material have shown promising results at mitigating the onset of the polarization phenomenon, likely linked to improved crystal quality and hole carrier transport. Better hole transport will have an impact on charge collection, particularly in pixelated detector designs and thick sensors (>1 mm). In this paper, the presence of charge sharing and the magnitude of charge loss were calculated for a 2 mm thick pixelated HF-CdZnTe detector with 250 μm pixel pitch and 25 μm pixel gaps, bonded to the STFC HEXITEC ASIC. Results are compared with a CdTe detector as a reference point and supported with simulations from a Monte-Carlo detector model. Charge sharing events showed minimal charge loss in the HF-CdZnTe, resulting in a spectral resolution of 1.63 ± 0.08 keV Full Width at Half Maximum (FWHM) for bipixel charge sharing events at 59.5 keV. Depth of interaction effects were shown to influence charge loss in shared events. The performance is discussed in relation to the improved hole transport of HF-CdZnTe and comparison with simulated results provided evidence of a uniform electric field. |
| first_indexed | 2024-03-10T11:36:26Z |
| format | Article |
| id | doaj.art-4b61f324360e4e748e9383dc66ab803e |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-03-10T11:36:26Z |
| publishDate | 2021-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-4b61f324360e4e748e9383dc66ab803e2023-11-21T18:47:52ZengMDPI AGSensors1424-82202021-05-01219326010.3390/s21093260Charge Sharing and Charge Loss in High-Flux Capable Pixelated CdZnTe DetectorsKjell A. L. Koch-Mehrin0Sarah L. Bugby1John E. Lees2Matthew C. Veale3Matthew D. Wilson4Space Research Centre, Department of Physics & Astronomy, University of Leicester, Leicester LE1 7RH, UKCentre for Imaging Science, Department of Physics, Loughborough University, Loughborough LE11 3TU, UKSpace Research Centre, Department of Physics & Astronomy, University of Leicester, Leicester LE1 7RH, UKSTFC Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, UKSTFC Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, UKCadmium zinc telluride (CdZnTe) detectors are known to suffer from polarization effects under high photon flux due to poor hole transport in the crystal material. This has led to the development of a high-flux capable CdZnTe material (HF-CdZnTe). Detectors with the HF-CdZnTe material have shown promising results at mitigating the onset of the polarization phenomenon, likely linked to improved crystal quality and hole carrier transport. Better hole transport will have an impact on charge collection, particularly in pixelated detector designs and thick sensors (>1 mm). In this paper, the presence of charge sharing and the magnitude of charge loss were calculated for a 2 mm thick pixelated HF-CdZnTe detector with 250 μm pixel pitch and 25 μm pixel gaps, bonded to the STFC HEXITEC ASIC. Results are compared with a CdTe detector as a reference point and supported with simulations from a Monte-Carlo detector model. Charge sharing events showed minimal charge loss in the HF-CdZnTe, resulting in a spectral resolution of 1.63 ± 0.08 keV Full Width at Half Maximum (FWHM) for bipixel charge sharing events at 59.5 keV. Depth of interaction effects were shown to influence charge loss in shared events. The performance is discussed in relation to the improved hole transport of HF-CdZnTe and comparison with simulated results provided evidence of a uniform electric field.https://www.mdpi.com/1424-8220/21/9/3260CdZnTepixel detectorX-ray detectorcharge sharingcharge loss |
| spellingShingle | Kjell A. L. Koch-Mehrin Sarah L. Bugby John E. Lees Matthew C. Veale Matthew D. Wilson Charge Sharing and Charge Loss in High-Flux Capable Pixelated CdZnTe Detectors Sensors CdZnTe pixel detector X-ray detector charge sharing charge loss |
| title | Charge Sharing and Charge Loss in High-Flux Capable Pixelated CdZnTe Detectors |
| title_full | Charge Sharing and Charge Loss in High-Flux Capable Pixelated CdZnTe Detectors |
| title_fullStr | Charge Sharing and Charge Loss in High-Flux Capable Pixelated CdZnTe Detectors |
| title_full_unstemmed | Charge Sharing and Charge Loss in High-Flux Capable Pixelated CdZnTe Detectors |
| title_short | Charge Sharing and Charge Loss in High-Flux Capable Pixelated CdZnTe Detectors |
| title_sort | charge sharing and charge loss in high flux capable pixelated cdznte detectors |
| topic | CdZnTe pixel detector X-ray detector charge sharing charge loss |
| url | https://www.mdpi.com/1424-8220/21/9/3260 |
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