Incomplete charge collection at inter-pixel gap in low- and high-flux cadmium zinc telluride pixel detectors

DOI: 10.3390/s22041441

Authors: Antonino Buttacavoli (University of Palermo) , Fabio Principato (University of Palermo) , Gaetano Gerardi (University of Palermo) , Donato Cascio (University of Palermo) , Giuseppe Raso (University of Palermo) , Manuele Bettelli (IMEM/CNR) , Andrea Zappettini (IMEM/CNR) , Paul Seller (UKRI Science & Technology Facilities Council) , Matthew Veale (UKRI Science & Technology Facilities Council) , Leonardo Abbene (University of Palermo)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Sensors , VOL 22

State: Published (Approved)
Published: February 2022
Diamond Proposal Number(s): 20545

Abstract: The success of cadmium zinc telluride (CZT) detectors in room-temperature spectroscopic X-ray imaging is now widely accepted. The most common CZT detectors are characterized by enhanced-charge transport properties of electrons, with mobility-lifetime products μeτe > 10−2 cm2/V and μhτh > 10−5 cm2/V. These materials, typically termed low-flux LF-CZT, are successfully used for thick electron-sensing detectors and in low-flux conditions. Recently, new CZT materials with hole mobility-lifetime product enhancements (μhτh > 10−4 cm2/V and μeτe > 10−3 cm2/V) have been fabricated for high-flux measurements (high-flux HF-CZT detectors). In this work, we will present the performance and charge-sharing properties of sub-millimeter CZT pixel detectors based on LF-CZT and HF-CZT crystals. Experimental results from the measurement of energy spectra after charge-sharing addition (CSA) and from 2D X-ray mapping highlight the better charge-collection properties of HF-CZT detectors near the inter-pixel gaps. The successful mitigation of the effects of incomplete charge collection after CSA was also performed through original charge-sharing correction techniques. These activities exist in the framework of international collaboration on the development of energy-resolved X-ray scanners for medical applications and non-destructive testing in the food industry.

Journal Keywords: CZT detectors; charge sharing; incomplete charge collection; charge-sharing correction; semiconductor pixel detectors

Subject Areas: Physics


Instruments: B16-Test Beamline

Added On: 24/02/2022 08:59

Documents:
sensors-22-01441.pdf

Discipline Tags:

Detectors Physics Engineering & Technology

Technical Tags:

Diffraction