Abstract
The application of Cd0.9Zn0.1Te (CZT) single crystals, the primary choice for high-resolution, room-temperature compact gamma-ray detectors in the field of medical imaging and homeland security for the past three decades, is limited by the high cost of production and maintenance due to low detector grade crystal growth yield. The recent advent of its quaternary successor, Cd0.9Zn0.1Te1−ySey (CZTS), has exhibited remarkable crystal growth yield above 90% compared to that of ~33% for CZT. The inclusion of Se in appropriate stoichiometry in the CZT matrix is responsible for reducing the concentration of sub-grain boundary (SGB) networks which greatly enhances the compositional homogeneity and growth yield. SGB networks also host defect centers responsible for charge trapping, hence their reduced concentration ensures minimized charge trapping. Indeed, CZTS single crystals have shown remarkable improvement in electron charge transport properties and energy resolution over CZT detectors. However, our studies have found that the overall charge transport in CZTS is still limited by the hole trapping. In this article, we systematically review the advances in the CZTS growth techniques, its performance as room-temperature radiation detector, and the role of defects and their passivation studies needed to improve the performance of CZTS detectors further.
Highlights
Penetrating radiations such as x- and γ-rays are indispensable for medical imaging through techniques such as computed tomography (CT), positron emission tomography (PET) or X-ray radiography, for security screening at the port of entries, for monitoring and safeguarding of special nuclear materials, to name a few [1,2]
We review the advances in Cd0.9Zn1.0Te1−ySey quaternary wide bandgap high-Z semiconductor for room-temperature high-energy gamma-ray detection since its inception as a high-resolution detector in the middle of the last decade
Its ternary predecessor CZT, despite its high-resolution performance, had always demonstrated low crystal growth yield resulting in high production costs
Summary
Penetrating radiations such as x- and γ-rays are indispensable for medical imaging through techniques such as computed tomography (CT), positron emission tomography (PET) or X-ray radiography, for security screening at the port of entries, for monitoring and safeguarding of special nuclear materials, to name a few [1,2]. CZT detectors have reigned for the past three decades as direct conversion detectors at room-temperature for specialized applications in medical imaging and scanning, homeland security, nuclear non-proliferation, accounting and safeguarding of nuclear wastes, and special nuclear materials [10]. Crystal growth methods such as the travelling heater method (THM) [11,12,13] and vertical Bridgman method (VBM) [14,15,16] are the primary techniques to grow detector-grade CZT single crystals.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
